| Business | Phone |
| Aha Consulting Engineers 10 Maguire Rd # 121, Lexington 2421 | (781) 372-3000 |
| Arinc Engineering Svc 70 Westview St # 2, Lexington 2421 | (781) 860-4500 |
| Tos Systems Inc 15 Valley Rd, Lexington 2421 | (781) 861-9018 |
| Stellar Corp 594 Marrett Rd # 10, Lexington 2421 | (781) 863-0101 |
| Excelsior Engineer Enterprises Lexington 2421 | (781) 861-1010 |
| Fws Engineering 54 Ledgelawn Ave, Lexington 2420 | (781) 862-0607 |
| Rapperport Associates 8 Wallis Ct, Lexington 2421 | (781) 862-9001 |