| Business | Phone |
| Colonial Electric Supply 485 S Henderson Rd, King Of Prussia 19406 | (610) 312-8100 |
| Colonial Electric Supply Corp 201 E Church Rd, King Of Prussia 19406 | (610) 265-3636 |
| Elect Test Fixtures 470 Drew Ct, King Of Prussia 19406 | (610) 278-9861 |
| Electro-Science Laboratories 416 E Church Rd, King Of Prussia 19406 | (610) 272-8000 |