| Allied Electronics | 70174999 | 1 | | 1 | |
 Newark | 96F6507 | 1 | 521 | 1 | 1 @ $0.43, 10 @ $0.34 |
| Crescent Electric Supply Co | SY4S-51F1 | 1 | | 1 | |
 Digi-Key | 1885-1305-ND | 1 | 976 | 1 | 1 @ $0.38, 10 @ $0.36, 25 @ $0.32, 50 @ $0.30, 100 @ $0.29, 250 @ $0.26, 500 @ $0.24, 1000 @ $0.22, 5000 @ $0.22 |
| 1Source | SY4S-51F1 | 1 | | 1 | |
 Platt.com | 0029068 | 1 | | 1 | |
 Carlton Bates Company | 78040098887 | 1 | 153 | 1 | 1 @ $0.39 |
 ExcessParts.Net | SY4S-51F1 | 1 | 55 | 1 | 1 @ $0.46 |
 Walker Industrial | SY4S-51F1 | 1 | 3 to 5 Business Days | 1 | 1 @ $0.24 |
| RS Delivers | 2508800921 | 1 | | 1 | |
 Component Electronics | 725-18 | 1 | 11 | 1 | 1 @ $0.38, 50 @ $0.32, 100 @ $0.29, 500 @ $0.27, 1000 @ $0.25 |
| Digi-Key | 8344570 | 1 | | 1 | |
| Kele | SY4S-51F1 | 1 | | 1 | 1 @ $0.47 |
 Onlinecomponents.com | SY4S-51F1 | 70 | 2503 | 1 | 70 @ $0.35, 1000 @ $0.26, 10000 @ $0.25 |
 steinerelectric.com | 29594 | 1 | | 1 | 1 @ $0.42 |
 ebay.com_safecomponents | SY4S-51F1 | 1 | -2 | 1 | 1 @ $102.86 |
 ebay.com_indyscubadiveralex | SY4S-51F1 | 1 | -2 | 1 | 1 @ $107.99 |
 ebay.com_plccenter | SY4S-51F1 | 1 | -2 | 1 | 1 @ $102.62 |
| Crescent Electric Supply Co | 2100223 | 1 | | 1 | |
| us.rs-online.com | 70174999 | 1 | 224 | 1 | 1 @ $0.47, 10 @ $0.44, 25 @ $0.43, 50 @ $0.41 |
 Galco | SY4S-51F1-IDEC | 1 | 138 | 1 | 1 @ $0.00 |
| Airline Hydraulics | IDEC SY4S-51F1 | 1 | | 1 | 1 @ $0.36 |
 jotrin.com | JT33-SY4S-51F1 | 1 | 12300 | 1 | |
