| Business | Phone |
| Engineering Design Svc Chatsworth 91311 | (818) 341-4341 |
| Tetracam Inc 21601 Devonshire St, Chatsworth 91311 | (818) 718-7103 |
| Uniplan Engineering Inc 9310 Topanga Canyon Blvd, Chatsworth 91311 | (818) 407-5880 |
| Znc Engineering & Manufacturer 20542 Plummer St, Chatsworth 91311 | (818) 772-1761 |