| Business | Phone |
| Cabe Associates Inc 144 S Governors Ave, Dover 19904 | (302) 674-9280 |
| Landmark Engineering Inc 29 S State St, Dover 19901 | (302) 734-9597 |
| Mc Crone Inc 111 S West St # 6, Dover 19904 | (302) 730-4600 |
| Scott Engineering Inc 838 Walker Rd # 21-2, Dover 19904 | (302) 736-3058 |