| Business | Phone |
| Applied Proteomics 18231 Flower Hill Way, Gaithersburg 20879 | (301) 330-2030 |
| Axes Corp 818 W Diamond Ave, Gaithersburg 20878 | (301) 947-5696 |
| B A Engineering Inc 9705 Hickory Spring Ln, Gaithersburg 20882 | (301) 391-6130 |
| Casey Engineering Ii Gaithersburg 20877 | (301) 948-3568 |
| Cetrom Engineering Svc 818 W Diamond Ave # 300, Gaithersburg 20878 | (301) 990-4111 |
| Danac Corp 7600 Rickenbacker Dr # H, Gaithersburg 20879 | (301) 948-6730 |
| Mullaney Engineering Inc 9049 Shady Grove Ct, Gaithersburg 20877 | (301) 921-0115 |
| Harvey-Cleary Engineers 101 Orchard Ridge Dr # 325, Gaithersburg 20878 | (301) 519-2288 |