| Business | Phone |
| Polytronics Engineering Ltd 87 Page Ave, North York M2K 2B8 | (416) 225-2026 |
| Electronic Structures 9 Saddletree Dr, North York M2H 3L1 | (416) 497-9810 |
| Electrocraft Systems 107 Larkfield Dr, North York M3B 2H6 | (416) 391-5958 |
| G & J Electronics Inc 6 Dornfell St, North York M2R 2Y6 | (416) 733-0528 |