| Business | Phone |
| Vanguard Research 4916 State Road 83, Hartland 53029 | (262) 369-0370 |
| Engineered Solutions Inc N78w29098 Flynn Rd, Hartland 53029 | (262) 538-4097 |
| Jendusa Engineering Assoc Inc 4615 Vettelson Rd, Hartland 53029 | (262) 369-0700 |
| Land Tech Engineering 720 Industrial Ct, Hartland 53029 | (262) 367-7599 |