The M75 armored infantry vehicle was based on the chassis of the cargo tractor T43E1, which used the same suspension as the 76mm gun tank M41. M75 resembled a box on tracks, as many armored personnel carriers do, and its exhaust pipe emerged from the front of the vehicle's roof and vented the engine exhaust to the right. The brush guard for the right headlight cluster was extended to protect the tailpipe as well later in the production run. Early M75s had thinner roof armor at .375" (.953cm) and thicker floor armor at 1.25" (3.18cm), and the first two and last two road wheels on each track were dampened with shock absorbers on early vehicles. The driver and commander each had a vision cupola, and the driver's could be equipped with an infrared periscope in late vehicles. Two large hinged rear roof doors opened towards the center of the vehicle over the passenger compartment, and infantry access was provided by two large doors in the rear of the hull.