| Business | Phone |
| Alert Security 204 Beverley Glen Blvd, Thornhill L4J 7T5 | (905) 889-4419 |
| Jam Electronic Co 167 Clark Ave, Thornhill L3T 4Y7 | (905) 763-2125 |
| R & R Alarm Systems 31 Brewsland Cres, Thornhill L3T 7G8 | (905) 731-8817 |
| Sinai Security Systems Ltd 36 Jenstar Way, Thornhill L4J 5W3 | (905) 731-3292 |
| Day-Night Alarms 44 Lilac Ave, Thornhill L3T 5K2 | (905) 771-8160 |