液晶元件 11.0592MHz 18pF 20ppm -20C +70C
ECS-110.5-18-23B-JTM-TR
ECS
1:
HK$9.12
456 庫存量
Mouser 元件編號
520-110.5-18-23BJTMT
ECS
液晶元件 11.0592MHz 18pF 20ppm -20C +70C
456 庫存量
1
HK$9.12
10
HK$7.80
25
HK$7.41
100
HK$6.73
1,000
HK$5.81
2,000
檢視
250
HK$6.07
500
HK$5.88
2,000
HK$5.56
5,000
HK$5.38
購買
最少: 1
倍數: 1
捲 :
1,000
詳細資料
11.0592 MHz
18 pF
20 PPM
20 PPM
6 mm x 3.5 mm
- 20 C
+ 70 C
SMD/SMT
80 Ohms
100 uW
6 mm
3.5 mm
1.1 mm
ECX-64
Reel, Cut Tape, MouseReel
液晶元件 48MHz 18pF ESR 50 20ppm -20C +70C
ECS-480-18-23B-JTM-TR
ECS
1:
HK$9.12
25 庫存量
Mouser 元件編號
520-480-18-23B-JTMT
ECS
液晶元件 48MHz 18pF ESR 50 20ppm -20C +70C
25 庫存量
1
HK$9.12
10
HK$7.80
25
HK$7.41
100
HK$6.73
1,000
HK$5.15
2,000
檢視
250
HK$6.07
500
HK$5.88
2,000
HK$4.94
5,000
HK$4.76
購買
最少: 1
倍數: 1
捲 :
1,000
詳細資料
48 MHz
18 pF
20 PPM
20 PPM
6 mm x 3.5 mm
- 20 C
+ 70 C
SMD/SMT
30 Ohms
500 uW
6 mm
3.5 mm
1.1 mm
ECX-64
Reel, Cut Tape, MouseReel
液晶元件 10MHz 18pF ESR 50 20ppm -20C +70C
ECS-100-18-23B-JTM-TR
ECS
1:
HK$8.06
234 庫存量
Mouser 元件編號
520-100-18-23B-JTMT
ECS
液晶元件 10MHz 18pF ESR 50 20ppm -20C +70C
234 庫存量
1
HK$8.06
10
HK$7.00
25
HK$6.35
100
HK$6.08
1,000
HK$5.28
2,000
檢視
250
HK$5.75
500
HK$5.52
2,000
HK$4.94
5,000
HK$4.67
購買
最少: 1
倍數: 1
捲 :
1,000
詳細資料
10 MHz
18 pF
20 PPM
20 PPM
6 mm x 3.5 mm
- 20 C
+ 70 C
SMD/SMT
80 Ohms
500 uW
6 mm
3.5 mm
1.1 mm
ECX-64
Reel, Cut Tape, MouseReel
液晶元件 10MHz 18pF ESR 50 20ppm -40C +85C
ECS-100-18-23B-JTN-TR
ECS
1:
HK$7.89
1,323 庫存量
Mouser 元件編號
520-100-18-23B-JTNT
ECS
液晶元件 10MHz 18pF ESR 50 20ppm -40C +85C
1,323 庫存量
1
HK$7.89
10
HK$6.82
25
HK$6.19
100
HK$5.93
1,000
HK$5.15
2,000
檢視
250
HK$5.61
500
HK$5.38
2,000
HK$4.82
5,000
HK$4.64
購買
最少: 1
倍數: 1
捲 :
1,000
詳細資料
10 MHz
18 pF
20 PPM
20 PPM
6 mm x 3.5 mm
- 40 C
+ 85 C
SMD/SMT
80 Ohms
500 uW
6 mm
3.5 mm
1.1 mm
ECX-64
Reel, Cut Tape, MouseReel
液晶元件 12MHz 18pF ESR 50 20ppm -20C +70C
ECS-120-18-23B-JTM-TR
ECS
1:
HK$8.06
1,033 庫存量
Mouser 元件編號
520-120-18-23B-JTMT
ECS
液晶元件 12MHz 18pF ESR 50 20ppm -20C +70C
1,033 庫存量
1
HK$8.06
10
HK$7.00
25
HK$6.35
100
HK$6.08
1,000
HK$5.28
2,000
檢視
250
HK$5.75
500
HK$5.52
2,000
HK$4.94
5,000
HK$4.66
購買
最少: 1
倍數: 1
捲 :
1,000
詳細資料
12 MHz
18 pF
20 PPM
20 PPM
6 mm x 3.5 mm
- 20 C
+ 70 C
SMD/SMT
50 Ohms
100 uW
6 mm
3.5 mm
1.1 mm
ECX-64
Reel, Cut Tape, MouseReel
液晶元件 CRYSTAL 12.0000MHZ 20PF SMD,ECX-64B,50ppm,30ppm,20pF,80 Ohm,Fundamental,-10C - 70C,4-SMD, No Lead (DFN, LCC),0.236" L x 0.138" W (6.00mm x 3.50mm),0.043" (1.10mm)
ECS-120-20-23B-TR
ECS
1:
HK$7.64
963 庫存量
Mouser 元件編號
520-120-20-23B-TR
ECS
液晶元件 CRYSTAL 12.0000MHZ 20PF SMD,ECX-64B,50ppm,30ppm,20pF,80 Ohm,Fundamental,-10C - 70C,4-SMD, No Lead (DFN, LCC),0.236" L x 0.138" W (6.00mm x 3.50mm),0.043" (1.10mm)
963 庫存量
1
HK$7.64
10
HK$6.64
25
HK$6.03
100
HK$5.78
1,000
HK$5.01
2,000
檢視
250
HK$5.47
500
HK$5.24
2,000
HK$4.69
5,000
HK$4.55
購買
最少: 1
倍數: 1
捲 :
1,000
詳細資料
12 MHz
20 pF
30 PPM
50 PPM
6 mm x 3.5 mm
- 10 C
+ 70 C
SMD/SMT
50 Ohms
100 uW
6 mm
3.5 mm
1.1 mm
ECX-64
Reel, Cut Tape, MouseReel
液晶元件 14.7456MHz 20pF 30ppm -10C +70C
ECS-147-20-23B-TR
ECS
1:
HK$8.06
960 庫存量
Mouser 元件編號
520-147-20-23B-TR
ECS
液晶元件 14.7456MHz 20pF 30ppm -10C +70C
960 庫存量
1
HK$8.06
10
HK$6.99
25
HK$6.34
100
HK$6.07
1,000
HK$5.16
2,000
檢視
250
HK$5.75
500
HK$5.51
2,000
HK$4.87
5,000
HK$4.64
購買
最少: 1
倍數: 1
捲 :
1,000
詳細資料
14.7456 MHz
20 pF
30 PPM
50 PPM
6 mm x 3.5 mm
- 10 C
+ 70 C
SMD/SMT
40 Ohms
100 uW
6 mm
3.5 mm
1.1 mm
ECX-64
Reel, Cut Tape, MouseReel
液晶元件 14.7456MHz 18pF 20ppm -20C +70C
ECS-147.4-18-23B-JTM-TR
ECS
1:
HK$7.73
611 庫存量
Mouser 元件編號
520-147.4-18-23BJTMT
ECS
液晶元件 14.7456MHz 18pF 20ppm -20C +70C
611 庫存量
1
HK$7.73
10
HK$6.74
25
HK$6.12
100
HK$5.86
1,000
HK$5.16
2,000
檢視
250
HK$5.54
2,000
HK$4.87
5,000
HK$4.64
購買
最少: 1
倍數: 1
捲 :
1,000
詳細資料
14.7456 MHz
18 pF
20 PPM
20 PPM
6 mm x 3.5 mm
- 20 C
+ 70 C
SMD/SMT
40 Ohms
100 uW
6 mm
3.5 mm
1.1 mm
ECX-64
Reel, Cut Tape, MouseReel
液晶元件 16MHz 18pF ESR 50 20ppm -20C +70C
ECS-160-18-23B-JTM-TR
ECS
1:
HK$7.40
967 庫存量
Mouser 元件編號
520-160-18-23B-JTMT
ECS
液晶元件 16MHz 18pF ESR 50 20ppm -20C +70C
967 庫存量
1
HK$7.40
10
HK$6.45
25
HK$5.85
100
HK$5.61
1,000
HK$4.87
2,000
檢視
250
HK$5.30
500
HK$5.09
2,000
HK$4.59
5,000
HK$4.41
購買
最少: 1
倍數: 1
捲 :
1,000
詳細資料
16 MHz
18 pF
20 PPM
20 PPM
6 mm x 3.5 mm
- 20 C
+ 70 C
SMD/SMT
50 Ohms
100 uW
6 mm
3.5 mm
1.1 mm
ECX-64
Reel, Cut Tape, MouseReel
液晶元件 CRYSTAL 16.0000MHZ 20PF SMD,ECX-64B,50ppm,30ppm,20pF,60 Ohm,Fundamental,-10C - 70C,4-SMD, No Lead (DFN, LCC),0.236" L x 0.138" W (6.00mm x 3.50mm),0.043" (1.10mm)
ECS-160-20-23B-TR
ECS
1:
HK$8.06
1,026 庫存量
Mouser 元件編號
520-160-20-23B-TR
ECS
液晶元件 CRYSTAL 16.0000MHZ 20PF SMD,ECX-64B,50ppm,30ppm,20pF,60 Ohm,Fundamental,-10C - 70C,4-SMD, No Lead (DFN, LCC),0.236" L x 0.138" W (6.00mm x 3.50mm),0.043" (1.10mm)
1,026 庫存量
1
HK$8.06
10
HK$7.00
25
HK$6.35
100
HK$6.08
1,000
HK$5.51
2,000
檢視
250
HK$5.75
500
HK$5.52
2,000
HK$4.89
5,000
HK$4.64
購買
最少: 1
倍數: 1
捲 :
1,000
詳細資料
16 MHz
20 pF
30 PPM
50 PPM
6 mm x 3.5 mm
- 10 C
+ 70 C
SMD/SMT
40 Ohms
100 uW
6 mm
3.5 mm
1.1 mm
ECX-64
Reel, Cut Tape, MouseReel
液晶元件 20MHz 18pF ESR 50 20ppm -20C +70C
ECS-200-18-23B-JTM-TR
ECS
1:
HK$7.97
958 庫存量
Mouser 元件編號
520-200-18-23B-JTMT
ECS
液晶元件 20MHz 18pF ESR 50 20ppm -20C +70C
958 庫存量
1
HK$7.97
10
HK$6.96
25
HK$6.31
100
HK$6.06
1,000
HK$5.20
2,000
檢視
500
HK$5.88
2,000
HK$4.87
5,000
HK$4.64
購買
最少: 1
倍數: 1
捲 :
1,000
詳細資料
20 MHz
18 pF
20 PPM
20 PPM
6 mm x 3.5 mm
- 20 C
+ 70 C
SMD/SMT
50 Ohms
500 uW
6 mm
3.5 mm
1.1 mm
ECX-64
Reel, Cut Tape, MouseReel
液晶元件 CRYSTAL 20.0000MHZ 20PF SMD,ECX-64B,50ppm,30ppm,20pF,40 Ohm,Fundamental,-10C - 70C,4-SMD, No Lead (DFN, LCC),0.236" L x 0.138" W (6.00mm x 3.50mm),0.043" (1.10mm)
ECS-200-20-23B-TR
ECS
1:
HK$8.06
649 庫存量
Mouser 元件編號
520-200-20-23B-TR
ECS
液晶元件 CRYSTAL 20.0000MHZ 20PF SMD,ECX-64B,50ppm,30ppm,20pF,40 Ohm,Fundamental,-10C - 70C,4-SMD, No Lead (DFN, LCC),0.236" L x 0.138" W (6.00mm x 3.50mm),0.043" (1.10mm)
649 庫存量
1
HK$8.06
10
HK$7.00
25
HK$6.35
100
HK$6.08
1,000
HK$5.10
2,000
檢視
250
HK$5.75
500
HK$5.52
2,000
HK$4.80
5,000
HK$4.57
購買
最少: 1
倍數: 1
捲 :
1,000
詳細資料
20 MHz
20 pF
30 PPM
50 PPM
6 mm x 3.5 mm
- 10 C
+ 70 C
SMD/SMT
30 Ohms
100 uW
6 mm
3.5 mm
1.1 mm
ECX-64
Reel, Cut Tape, MouseReel
液晶元件 24MHz 18pF ESR 50 20ppm -20C +70C
ECS-240-18-23B-JTM-TR
ECS
1:
HK$7.89
91 庫存量
1,000 預期29/5/2026
Mouser 元件編號
520-240-18-23B-JTMT
ECS
液晶元件 24MHz 18pF ESR 50 20ppm -20C +70C
91 庫存量
1,000 預期29/5/2026
1
HK$7.89
10
HK$6.89
25
HK$6.25
100
HK$5.99
1,000
HK$5.28
2,000
檢視
250
HK$5.66
500
HK$5.43
2,000
HK$4.87
5,000
HK$4.64
購買
最少: 1
倍數: 1
捲 :
1,000
詳細資料
24 MHz
18 pF
20 PPM
20 PPM
6 mm x 3.5 mm
- 20 C
+ 70 C
SMD/SMT
50 Ohms
500 uW
6 mm
3.5 mm
1.1 mm
ECX-64
Reel, Cut Tape, MouseReel
液晶元件 CRYSTAL 25.0000MHZ 18PF SMD,ECX-64B,50ppm,30ppm,18pF,40 Ohm,Fundamental,-10C - 70C,4-SMD, No Lead (DFN, LCC),0.236" L x 0.138" W (6.00mm x 3.50mm),0.043" (1.10mm)
ECS-250-18-23B-F-TR
ECS
1:
HK$8.06
1,013 庫存量
Mouser 元件編號
520-250-18-23B-F-TR
ECS
液晶元件 CRYSTAL 25.0000MHZ 18PF SMD,ECX-64B,50ppm,30ppm,18pF,40 Ohm,Fundamental,-10C - 70C,4-SMD, No Lead (DFN, LCC),0.236" L x 0.138" W (6.00mm x 3.50mm),0.043" (1.10mm)
1,013 庫存量
1
HK$8.06
10
HK$7.00
25
HK$6.35
100
HK$6.08
1,000
HK$5.81
2,000
檢視
250
HK$6.07
500
HK$5.88
2,000
HK$4.85
5,000
HK$4.64
購買
最少: 1
倍數: 1
捲 :
1,000
詳細資料
25 MHz
18 pF
30 PPM
50 PPM
6 mm x 3.5 mm
- 10 C
+ 70 C
SMD/SMT
30 Ohms
100 uW
6 mm
3.5 mm
1.1 mm
ECX-64
Reel, Cut Tape, MouseReel
液晶元件 25MHz 18pF ESR 50 20ppm -20C +70C
ECS-250-18-23B-JTM-TR
ECS
1:
HK$7.40
1,554 庫存量
Mouser 元件編號
520-250-18-23B-JTMT
ECS
液晶元件 25MHz 18pF ESR 50 20ppm -20C +70C
1,554 庫存量
1
HK$7.40
10
HK$6.40
25
HK$5.80
100
HK$5.56
1,000
HK$4.83
2,000
檢視
250
HK$5.26
500
HK$5.05
2,000
HK$4.59
5,000
HK$4.38
購買
最少: 1
倍數: 1
捲 :
1,000
詳細資料
25 MHz
18 pF
20 PPM
20 PPM
6 mm x 3.5 mm
- 20 C
+ 70 C
SMD/SMT
30 Ohms
100 uW
6 mm
3.5 mm
1.1 mm
ECX-64
Reel, Cut Tape, MouseReel
液晶元件 25MHz 18pF ESR 50 20ppm -40C +85C
ECS-250-18-23B-JTN-TR
ECS
1:
HK$8.06
1,227 庫存量
Mouser 元件編號
520-250-18-23B-JTNT
ECS
液晶元件 25MHz 18pF ESR 50 20ppm -40C +85C
1,227 庫存量
1
HK$8.06
10
HK$7.00
25
HK$6.35
100
HK$6.08
1,000
HK$5.51
2,000
檢視
250
HK$5.75
500
HK$5.52
2,000
HK$4.94
5,000
HK$4.78
購買
最少: 1
倍數: 1
捲 :
1,000
詳細資料
25 MHz
18 pF
20 PPM
20 PPM
6 mm x 3.5 mm
- 40 C
+ 85 C
SMD/SMT
30 Ohms
100 uW
6 mm
3.5 mm
1.1 mm
ECX-64
Reel, Cut Tape, MouseReel
液晶元件 7.3728MHz 18pF 20ppm -20C +70C
ECS-73-18-23B-JTM-TR
ECS
1:
HK$7.40
1,737 庫存量
Mouser 元件編號
520-73-18-23B-JTMT
ECS
液晶元件 7.3728MHz 18pF 20ppm -20C +70C
1,737 庫存量
1
HK$7.40
10
HK$6.45
25
HK$5.85
100
HK$5.61
1,000
HK$5.08
2,000
檢視
250
HK$5.31
500
HK$5.29
2,000
HK$4.80
5,000
HK$4.57
購買
最少: 1
倍數: 1
捲 :
1,000
詳細資料
7.3728 MHz
18 pF
30 PPM
50 PPM
6 mm x 3.5 mm
- 20 C
+ 70 C
SMD/SMT
100 Ohms
100 uW
6 mm
3.5 mm
1.1 mm
ECX-64
Reel, Cut Tape, MouseReel
液晶元件 7.3728MHz 18pF 20ppm -40C +85C
ECS-73-18-23B-JTN-TR
ECS
1:
HK$7.64
80 庫存量
2,000 預期12/8/2026
Mouser 元件編號
520-73-18-23B-JTNT
ECS
液晶元件 7.3728MHz 18pF 20ppm -40C +85C
80 庫存量
2,000 預期12/8/2026
1
HK$7.64
10
HK$6.66
25
HK$6.04
100
HK$5.79
1,000
HK$4.94
2,000
檢視
500
HK$5.29
2,000
HK$4.93
5,000
HK$4.76
購買
最少: 1
倍數: 1
捲 :
1,000
詳細資料
7.3728 MHz
18 pF
30 PPM
50 PPM
6 mm x 3.5 mm
- 40 C
+ 85 C
SMD/SMT
100 Ohms
100 uW
6 mm
3.5 mm
1.1 mm
ECX-64
Reel, Cut Tape, MouseReel
液晶元件 8MHz 18pF ESR 50 20ppm -40C +85C
ECS-80-18-23B-JGN-TR
ECS
1:
HK$8.06
1,978 庫存量
Mouser 元件編號
520-80-18-23B-JGNT
ECS
液晶元件 8MHz 18pF ESR 50 20ppm -40C +85C
1,978 庫存量
1
HK$8.06
10
HK$7.00
25
HK$6.35
100
HK$6.08
1,000
HK$5.28
2,000
檢視
250
HK$5.75
500
HK$5.52
2,000
HK$4.94
5,000
HK$4.66
購買
最少: 1
倍數: 1
捲 :
1,000
詳細資料
8 MHz
18 pF
20 PPM
30 PPM
6 mm x 3.5 mm
- 40 C
+ 85 C
SMD/SMT
60 Ohms
100 uW
6 mm
3.5 mm
1.1 mm
ECX-64
Reel, Cut Tape, MouseReel
液晶元件 8MHz 18pF -20C +70C
ECS-80-18-23B-JTM-TR
ECS
1:
HK$8.06
1,036 庫存量
Mouser 元件編號
520-80-18-23B-JTMT
ECS
液晶元件 8MHz 18pF -20C +70C
1,036 庫存量
1
HK$8.06
10
HK$7.00
25
HK$6.35
100
HK$6.08
1,000
HK$5.28
2,000
檢視
250
HK$5.75
500
HK$5.52
2,000
HK$4.92
5,000
HK$4.67
購買
最少: 1
倍數: 1
捲 :
1,000
詳細資料
8 MHz
18 pF
20 PPM
20 PPM
6 mm x 3.5 mm
- 20 C
+ 70 C
SMD/SMT
60 Ohms
100 uW
6 mm
3.5 mm
1.1 mm
ECX-64
Reel, Cut Tape, MouseReel
液晶元件 14.31818MHz 20pF
ECS-143-20-23B-TR
ECS
1:
HK$7.81
866 庫存量
Mouser 元件編號
520-ECS-143-20-23BTR
ECS
液晶元件 14.31818MHz 20pF
866 庫存量
1
HK$7.81
10
HK$6.77
25
HK$6.13
100
HK$5.88
1,000
HK$5.22
2,000
檢視
250
HK$5.56
500
HK$5.33
2,000
HK$4.89
5,000
HK$4.64
購買
最少: 1
倍數: 1
捲 :
1,000
詳細資料
14.31818 MHz
20 pF
30 PPM
50 PPM
6 mm x 3.5 mm
- 10 C
+ 70 C
SMD/SMT
6 mm
3.5 mm
1.1 mm
ECX-64
Reel, Cut Tape, MouseReel
液晶元件 8MHz 18pF ESR 50 20ppm -40C +85C
ECS-80-18-23B-JTN-TR
ECS
1:
HK$8.06
2,000 在途量
Mouser 元件編號
520-80-18-23B-JTNT
ECS
液晶元件 8MHz 18pF ESR 50 20ppm -40C +85C
2,000 在途量
檢視日期
在途量:
1,000 預期7/7/2026
1,000 預期18/8/2026
1
HK$8.06
10
HK$6.97
25
HK$6.32
100
HK$6.06
1,000
HK$5.20
2,000
檢視
250
HK$5.73
500
HK$5.50
2,000
HK$4.87
5,000
HK$4.64
購買
最少: 1
倍數: 1
捲 :
1,000
詳細資料
8 MHz
18 pF
20 PPM
20 PPM
6 mm x 3.5 mm
- 40 C
+ 85 C
SMD/SMT
60 Ohms
100 uW
6 mm
3.5 mm
1.1 mm
ECX-64
Reel, Cut Tape, MouseReel
液晶元件 CRYSTAL 19.6608MHZ 20PF SMD,ECX-64B,50ppm,30ppm,20pF,60 Ohm,Fundamental,-10C - 70C,4-SMD, No Lead (DFN, LCC),0.236" L x 0.138" W (6.00mm x 3.50mm),0.043" (1.10mm)
ECS-196-20-23B-TR
ECS
1:
HK$9.86
無庫存前置作業時間 12 週
Mouser 元件編號
520-196-20-23B-TR
ECS
液晶元件 CRYSTAL 19.6608MHZ 20PF SMD,ECX-64B,50ppm,30ppm,20pF,60 Ohm,Fundamental,-10C - 70C,4-SMD, No Lead (DFN, LCC),0.236" L x 0.138" W (6.00mm x 3.50mm),0.043" (1.10mm)
無庫存前置作業時間 12 週
1
HK$9.86
10
HK$8.47
25
HK$7.85
100
HK$7.32
1,000
HK$6.34
2,000
檢視
250
HK$6.95
500
HK$6.85
2,000
HK$5.42
5,000
HK$5.24
購買
最少: 1
倍數: 1
捲 :
1,000
詳細資料
19.6608 MHz
20 pF
30 PPM
50 PPM
6 mm x 3.5 mm
- 10 C
+ 70 C
SMD/SMT
40 Ohms
100 uW
6 mm
3.5 mm
1.1 mm
ECX-64
Reel, Cut Tape, MouseReel
液晶元件 27MHz 18pF ESR 50 20ppm -20C +70C
ECS-270-18-23B-JTM-TR
ECS
1:
HK$8.06
無庫存前置作業時間 12 週
Mouser 元件編號
520-270-18-23B-JTMT
ECS
液晶元件 27MHz 18pF ESR 50 20ppm -20C +70C
無庫存前置作業時間 12 週
1
HK$8.06
10
HK$7.08
25
HK$6.77
100
HK$6.25
1,000
HK$5.28
2,000
檢視
250
HK$5.75
500
HK$5.60
2,000
HK$5.12
5,000
HK$4.65
購買
最少: 1
倍數: 1
捲 :
1,000
詳細資料
27 MHz
18 pF
20 PPM
20 PPM
6 mm x 3.5 mm
- 20 C
+ 70 C
SMD/SMT
50 Ohms
500 uW
6 mm
3.5 mm
1.1 mm
ECX-64
Reel, Cut Tape, MouseReel
液晶元件 CRYSTAL 12.0000MHZ 20PF SMD
ECS-120-20-23B
ECS
1,000:
HK$23.51
無庫存前置作業時間 12 週
Mouser 元件編號
520-ECS-120-20-23B
ECS
液晶元件 CRYSTAL 12.0000MHZ 20PF SMD
無庫存前置作業時間 12 週
備用包裝
購買
最少: 1,000
倍數: 1,000
詳細資料
12 MHz
20 pF
30 PPM
50 PPM / C
- 10 C
+ 70 C
SMD/SMT
50 Ohms
100 uW
6 mm
3.5 mm
1.1 mm
ECX-64
Bulk