| Business | Phone |
| Airpax Corp 550 Highland St, Frederick 21701 | (301) 663-5141 |
| American Microwave 7310 Grove Rd # 206, Frederick 21704 | (301) 682-6038 |
| American Microwave Corp 7311 Grove Rd # G, Frederick 21704 | (301) 662-4989 |
| Bhb Creative Cabling Inc 5702 Industry Ln # 842, Frederick 21704 | (301) 620-4257 |
| Branch Electric Supply Co 1559 Tilco Dr, Frederick 21704 | (301) 663-0800 |
| Fma Inc 5716 Industry Ln, Frederick 21704 | (301) 668-7614 |
| Secur-Data Systems Inc 4640 Wedgewood Blvd # 104, Frederick 21703 | (301) 698-9955 |
| Weinschel Corp 5305 Spectrum Dr, Frederick 21703 | (301) 846-9222 |