This is a bracket for Viair 91028 2.5 Gallon Air Tank (Six 1/4" NPT Ports, 200 PSI Rated) to mount it in 2019-2026 Ram 3500 DRW trucks with factory bed.
 
I've also visually checked a 2011 2500 Long Bed, and it appears that they are the same. So, it should theoretically work for any 2010-2026 Long Bed 2500 or 3500, single rear wheel or dually.
 
This bracket is made out of 1/8" P&O steel, laser cut and CNC formed. It ships bare steel. It also includes the hardware to mount to the truck and hardware to mount the tank to the bracket.
 
Air tank available here: https://amzn.to/4gPBYnD