This lock was used on Jayco, Starcraft, Winnebago and some other tent trailers.  It works on door 1" and thicker.

Outer plate is 2" wide x 4" high. Knob is 2.5" diameter.

Outer & inner half of one complete assembly. Laminated, all steel bolt self-tightening under vibration, and requires no slamming to secure door. Panic feature guarantees immediate emergency exit. Designed to fit all doors of any thickness.