| RS Delivers | 537-1048 | 0.294 | 1 | 3250 | | Eaton | | 0.294 @ 10 |
| Sager Electronics | BK1/S501-4-R | 0.516 | 1000 | 10 | | Eaton | | 0.516 @ 1000 |
| Waldom | Eaton Electronics BK1/S501-4-R | 0.56 | 95 | 15500 | | Eaton Electronics | | 0.56 @ 95 |
| Onlinecomponents.com | BK1-S501-4-R | 0.64 | 30 | 1200 | | Eaton | | 0.64 @ 30 |
| us.rs-online.com | 74057102 | 0.71 | 1000 | 10 | | Eaton Electronics | | 0.71 @ 1000 |
| Future Electronics | C007915532 | 0.834 | 1000 | 10 | | Eaton | | 0.834 @ 1000 |
  | Zoro | G306130651 | 0.92 | 10 | 10 | | Cooper Bussmann | | 0.92 @ 10 |
| Hotenda | H575179 | 1.305 | 1 | 10 | | Eaton (formerly Cooper Bussmann) | | 1.305 @ 10 |
  | Digi-Key | 283-3292-ND | 1.305 | 1 | 10 | | Eaton - Electronics Division | | 1.305 @ 10 |
  | Radwell | S501-4-R | 1.56 | 5 | 55 | | BUSSMANN | | 1.56 @ 10 |
  | Newark | 29AJ4162 | 1.56 | 10 | 1418 | | EATON BUSSMANN | | 1.56 @ 10 |
| specialtycontrolsystems.com | S501-4-R | 1.78 | 1 | 60 | | BUSSMAN | | 1.78 @ 10 |
  | Walker Industrial | S501-4-R | 2.19 | 5 | 10 | 17 | Cooper Bussmann | | 2.19 @ 10 |
  | AI Consolidated | S501-4-R-BUSSMANN | 2.38 | 1 | 10 | | Bussmann Eaton Cooper Fuses | 0.0187 | 2.38 @ 10 |
| Dale-Electric | S501-4-R | 2.4 | 1 | 10 | | Cooper Bussmann | | 2.4 @ 10 |
  | Galco | S501-4-R-BUSS | 3.94 | 5 | 10 | | Bussmann | 8.0 | 3.94 @ 10 |
| Mouser | 504-S501-4-R | 4.97 | 1 | 179 | | Cooper Bussmann | | 4.97 @ 10 |
| crescentelectric.com | 137638 | 5.04 | 1 | 10 | | Eaton Bussmann series | | 5.04 @ 10 |
| steinerelectric.com | 529487 | 5.18 | 1 | 10 | | BUSSMANN | | 5.18 @ 10 |
  | Platt.com | 0966678 | 5.23 | 1 | 10 | | Eaton/Bussmann Series | | 5.23 @ 10 |
| Graybar | 25142700 | 5.5552 | 5 | 10 | | Bussmann (Eaton) | | 5.5552 @ 10 |
| AmazonTP | B0040ZJ0SO | 6.16 | 1 | 10 | 20 | Cooper Bussmann | | 6.16 @ 10 |
| standardelectricsupply.com | 2293964 | 17.85 | 1 | 10 | | Bussmann | | 17.85 @ 10 |
  | sustainablesupply.com | C1176987 | 21.99 | 1 | 10 | | Eaton | 0.02 | 21.99 @ 10 |
  | simsupply.com | ZO-G1792061 | 22.72 | 1 | 97 | | Eaton Bussmann | | 22.72 @ 10 |
  | Raptor Supplies | AB8WTZ | 39.755313 | 1 | 10 | | BUSSMANN | | 39.755313 @ 10 |