This very comfortable tray was designed so that you can carve right in your lap. Requires use of the 4" hose adapter and a length of 4 inch flexible vent hose (available at hardware stores). But it is much more than just a lap tray. Stand it on edge and it excels at picking up dust from small stationary belt sanders and small grinders. The built-in lips are not only comfortable to rest your arms on, they can also be used to fashion the lap tray into a drawer that conveniently stores away under your desk or bench. Approximately 13"x17"x2"deep.