Shadow Box | 5" x 20" Short Sleeve20" Shadow Box with Short Sleeve *Please allow 1 2 days for this product to ship* Shadow boxes are perfect for installations where there is a gap between the walk in wall and the back of a wall mounted drip tray. A shadow box creates an extruded "pocket" in the walk in wall containing the beer shanks and the beer hose connections. You would utilize a shadow box to transfer cold air around the shanks instead of the beer heating up in uninsulated wall