| Business | Phone |
| Sonitrol Security Systems 3773 Corporate Centre Dr, Earth City 63045 | (314) 595-0100 |
| Security Equipment Supply Inc 3435 Rider Trl S, Earth City 63045 | (314) 298-8930 |
| Interface Security Systems 3773 Corporate Centre Dr, Earth City 63045 | (636) 946-6650 |
| Cssi 3773 Corporate Centre Dr, Earth City 63045 | (314) 892-6118 |