Looks like a short bed truck camper. Note the length of the bed in front of the wheel is about the same as the length of the bed behind the wheel. However, any short bed truck camper will fit on a long bed truck but will leave a gap between the front of the camper and the front of the bed. A spacer will need to be made to keep the camper from sliding forward.
The reason for this is the length difference between a short bed and long bed is all between the axle location and front of the bed. The bed design from the wheel wells rearward is the same between both models.