| Business | Phone |
| James Electronics Inc 4050 N Rockwell St, Chicago 60618 | (773) 463-6500 |
| Nanofast Inc 416 W Erie St, Chicago 60610 | (312) 943-4223 |
| Imperial Fabricators Co 3729 W Belmont Ave, Chicago 60618 | (773) 463-5522 |
| Mitron Manufacturing Co Inc 2614 W 48th St, Chicago 60632 | (773) 254-4200 |
| Voltronics Inc 7746 W Addison St, Chicago 60634 | (773) 625-1779 |
| Harber Industrials Inc 5000 W 73rd St, Chicago 60638 | (708) 594-7744 |
| Relay Service Co 1310 N Pulaski Rd, Chicago 60651 | (773) 252-2700 |