| Business | Phone |
| Niemann & Assoc 7958 S Madison St, Willowbrook 60527 | (630) 986-0931 |
| Securitas Security Systems 685 Executive Dr, Willowbrook 60527 | (630) 323-3068 |
| Security Equipment Supply 825 75th St H, Willowbrook 60527 | (630) 655-0039 |
| Sunrise Telecom Inc 7420 S County Line Rd, Willowbrook 60527 | (630) 789-7661 |
| V Ci Vena Consulting Inc 6526 Clarendon Hills Rd, Willowbrook 60527 | (630) 655-1879 |