Standard Wall Mount (CB-2012 / CB/4012): Allows you to mount it to the wall saving precious square footage. It also reduces clearance to the surface it is mounted to. Wall Mount with Sliding Tray (CB-2013 / CB-2213): Tray is used to catch any ashes or embers that may fall out of the stove when you are refilling it or manipulating the wood. Wall Mount with Fresh Air Intake (CB-2017 / CB2277): Works like the standard wall mount exceptit allows you to replace the air without the use of a window.It will bring the replacement air through a wall (or floor) through a 2” flex hose you would connect to the manifold found under the wall mount.