| Business | Phone |
| Communication Systems Inc 415 N 3rd St, Allentown 18102 | (610) 439-1600 |
| Educational Systems Svc 4500 S Cedarbrook Rd, Allentown 18103 | (610) 366-9103 |
| Vistacom 1902 Vultee St, Allentown 18103 | (610) 791-9081 |
| Visual Sound Inc 6330 Hedgewood Dr # 190, Allentown 18106 | (610) 391-9266 |
| Smith Stephen & Dean Visual 521t Benner Rd, Allentown 18104 | (610) 770-9377 |