| MRO Supply | 1376039 | 1 | | 1 | |
| Allied Electronics | 70150080 | 1 | | 1 | |
 Onlinecomponents.com | KTK-4 | 1 | 1 | 1 | 1 @ $23.20, 5 @ $21.27, 10 @ $19.63, 25 @ $18.76, 50 @ $17.97, 100 @ $16.79, 250 @ $16.36 |
| Grainger | 6F132 | 1 | | 1 | |
| RS Online | 8511205 | 1 | | 1 | |
| 1Source | KTK-4 | 1 | | 1 | |
 Walker Industrial | KTK-4 | 1 | 3 to 5 Days | 1 | 1 @ $35.44 |
 Platt.com | 0432979 | 1 | 103 | 1 | 1 @ $37.95 |
 Carlton Bates Company | 05171242024 | 1 | | 1 | 1 @ $22.32 |
| Fuses Unlimited | KTK-4 | 1 | 21 | 1 | |
 Digi-Key | 283-2462-ND | 1 | 18 | 1 | 1 @ $29.82, 5 @ $28.40, 10 @ $26.27, 50 @ $22.72, 100 @ $21.30, 250 @ $20.45 |
| Future Electronics | 4028368 | 1 | 13 | 1 | 1 @ $27.58, 4 @ $25.41, 15 @ $23.50, 40 @ $22.18, 100 @ $21.01 |
 AI Consolidated | KTK-4-BUSSMANN | 1 | -2 | 1 | 1 @ $18.89 |
 NRI Industrial | D392610 | 1 | | 1 | 1 @ $42.72 |
| FinditParts | 5950524 | 1 | | 1 | |
 Raptor Supplies | AE8QKA | 1 | | 1 | 1 @ $13.40 |
 AmazonTP | B01L6SKN9C | 1 | | 1 | 1 @ $9.99 |
 AmazonTP | B07RX2LG84 | 1 | | 1 | 1 @ $55.38 |
| AmazonTP | B0025QA71O | 1 | | 1 | 1 @ $9.99 |
| AmazonTP | B00MI7ELIA | 1 | | 1 | 1 @ $9.99 |
 Newark | 63R7760 | 10 | | 10 | 10 @ $53.60, 25 @ $49.14, 50 @ $44.67, 100 @ $42.45 |
| AmazonSC | B01L6SKN9C | 1 | | 1 | 1 @ $10.23 |
| AmazonSC | B01AL63176 | 1 | | 1 | |
| AmazonSC | B07RX2LG84 | 1 | | 1 | 1 @ $79.61 |
 bscsource.com | KTK4 | 1 | | 1 | 1 @ $17.99 |
| AmazonSC | B00MI7ELIA | 1 | | 1 | |
 grainger.ca | BUSKTK4 | 1 | | 1 | 1 @ $37.09 |
| Guardian | KTK-4 | 1 | | 1 | |
 NRI Industrial | D384292 | 1 | | 1 | 1 @ $45.39 |
| uri.com | KTK4 | 1 | | 1 | |
 kempstoncontrols.co.uk | KTK-4 | 1 | 30 | 1 | 1 @ $23.48 |
| Newark | 39AJ9899 | 1 | | 1 | |
| standardelectricsupply.com | 2320783 | 1 | | 1 | 1 @ $405.00 |
 Radwell | KTK-4 | 1 | 12 | 1 | 1 @ $32.00 |
 steinerelectric.com | 5022 | 1 | | 1 | 1 @ $27.45 |
 Kelly Hayes | KTK-4 | 1 | | 1 | 1 @ $17.51 |
| Widespread | KTK-4 | 1 | | 1 | |
| Superbreakers | KTK-4 | 1 | 70 | 1 | 1 @ $8.64 |
| Newark | 27P6359 | 1 | | 1 | |
| Crescent Electric Supply Co | 2140067 | 1 | | 1 | |
| RS Delivers | 851-1205 | 1 | 65 | 1 | 1 @ $59.10, 5 @ $54.96, 25 @ $51.36, 50 @ $48.23, 100 @ $45.45 |
| galesburgelectric.com | KTK-4 | 1 | | 1 | |
| Guardian | KTK4 | 1 | | 1 | |
 Galco | KTK-4-BUSS | 1 | | 1 | 1 @ $20.85 |
| Crescent Electric Supply Co | KTK-4 | 1 | | 1 | |
| us.rs-online.com | 70150080 | 1 | 9 | 1 | 1 @ $53.15, 5 @ $50.49, 10 @ $47.84, 50 @ $39.86 |
 National Supply Network | 74974080 | 10 | -2 | 10 | 1 @ $31.28 |
 Allfuses | KTK-4 | 1 | 502 | 1 | 1 @ $8.79 |
 crescentelectric.com | 158752 | 1 | | 1 | 1 @ $47.85 |
| Airline Hydraulics | BUSSMANN KTK-4 | 1 | | 1 | 1 @ $71.13 |
 Zoro | G0553804 | 1 | 771 | 1 | 1 @ $19.23 |
 simsupply.com | ZO-G0553804 | 1 | 797 | 1 | 1 @ $28.74 |