| Business | Phone |
| Alarm Systems Inc 510 Maine St 717, Quincy 62301 | (217) 222-2280 |
| Great River Products 1201 S 28th St, Quincy 62301 | (217) 223-3796 |
| Midwest Communications 110 S 11th St, Quincy 62301 | (217) 223-8556 |
| Special Control Systems 935 York St, Quincy 62301 | (217) 224-6663 |