| Business | Phone |
| Commercial Electronics Co 15524 New Hampshire Ave, Silver Spring 20905 | (301) 236-0300 |
| Adt Federal Systems 12053 Tech Rd, Silver Spring 20904 | (301) 622-6900 |
| University Landing Apt 1026 University Blvd E, Silver Spring 20903 | (301) 439-0389 |
| Unlimited Security Inc 8605 Cameron St # M-6, Silver Spring 20910 | (301) 650-2044 |
| B & B Security Consultants Inc 2401 Blueridge Ave, Silver Spring 20902 | (301) 933-6844 |
| Bti Security 8701 Georgia Ave, Silver Spring 20910 | (301) 562-9201 |
| Sherlock Security Silver Spring 20910 | (301) 587-6866 |
| Integer Security Corp 1110 Bonifant St, Silver Spring 20910 | (301) 495-0885 |