This is a like new Leer camper shell for a 2019-2026 (5th generation) Ram 2500/3500 with a 6'4" bed length. According to Google, the 4th Gen (2010-2018) are very similar with minor differences with the tailgate hinges and tail lights.
The last picture shows the model and serial number...any Leer dealer should be able to tell you if it will fit your truck or not.
This is the Leer 100XQ, which is the flagship of the Leer canopy line. It has one piece, tip out side windows with screens, frameless rear door with hidden hinges, interior headliner and a sliding front glass.
It is, obviously, white in color and I do have the key for it. This model retails for about $4500 depending on the options you get. If saving $1500 sounds good to you...Hit me up. I want it gone sooner than later.