| Business | Phone |
| Vantage Electronics Corp 681 Main St # 3-28, Waltham 2451 | (781) 894-8694 |
| Certeon Inc 235 Bear Hill Rd, Waltham 2451 | (781) 890-4750 |
| Chitron Electronics Inc 102 Clematis Ave # 1, Waltham 2453 | (781) 647-7700 |
| Omni Spectra Inc 140 4th Ave, Waltham 2451 | (781) 890-4750 |