Includes: housing, door, hinge, latch, gas cap, spout and install instructions. It can be installed in steel or fiberglass panels. Door is 3-1/2" x 4-3/4" oval. It's most common use is in the panels with a slight curvature like the quarter panels of most cars and trucks from the 1920's through cars of today. This part has a radius of 32 inches. The top is made of 18 gage mild steel. The spout is 2" o.d. and 3-3/4" long. Hinge is spring loaded to hold the door open and closed. Latch is spring loaded and magnetic. Part comes with spout, cap and pictured instructions.