Cabin (truck)
A sleeper (or sleeper berth or bunk) is a compartment attached to the cab where the driver can rest while not driving. It is frequently on long-haul semi-trailer trucks. They can range from a simple 2 to 4 foot (0.6 to 1.2 m) bunk to a 12-foot (3.7 m) apartment-on-wheels. It allows drivers to spend weeks on the road moving cargo.