| Business | Phone |
| 3-L Filters Ltd 427 Elgin St N, Cambridge N1R 8G4 | (519) 621-9949 |
| Kadar Filtration Svc 1710 Bishop St, Cambridge N1T 1T2 | (519) 621-4914 |
| Lakehead Manufacturing Inc 1721 Bishop, Cambridge | (519) 624-7004 |
| Fil-Trek Corp 120 Turnbull Crt, Cambridge N1T 1H9 | (519) 623-7448 |