| Business | Phone |
| American Industrial & Marine 3980 N Dupont Hwy, Dover 19901 | (302) 678-3657 |
| Magnum Electronics 913 Horsepond Rd, Dover 19901 | (302) 734-9250 |
| Redi-Call Communications Dover 19901 | (302) 678-3900 |
| Wireless Electronics Inc Dover 19901 | (302) 736-6697 |