Get your big rig equipped for the long haul with semi truck safety, air and electrical parts from 4 State Trucks. Whether you need semi truck electrical parts such as wiring and fuses, semi truck air line parts, or safety parts, we've got you covered. We offer a vast variety of high quality aftermarket semi truck parts available in stock and online. Make sure your big rig truck is ready for the road so that you can have a safe and successful journey.