| Business | Phone |
| Security Source Inc 6n760 Virginia Ct, Saint Charles 60174 | (847) 742-1100 |
| Connession Scientific Inc 41w584 Woodland Dr, Saint Charles 60175 | (630) 587-2873 |
| Engineered Security & Sound 473 Dunham Rd 219, Saint Charles 60174 | (630) 584-2324 |