EASY INSTALL: Takes less than an hour and will fit most trash chutes, including Acme, American, Century, Chutes International, Cutler, Hi-Rise Recycling Systems Inc., Midland, US, Valiant, Western, Wilkinson, & Nycor DURABLE: The door is manufactured with #4 Stainless Steel with a 16 gauge frame and 18 gauge trim for increased strength and durability FIRE RATED: It will withstand 1.5 Hours at 250 degrees Fahrenheit and is UL approved to comply with the latest national building codes SELF CLOSING: Our doors are noiseless and self closing by means of automatic door closer / hydraulic piston DIMENSIONS: When selecting a size please measure the door panel not the wall opening. (Flap Not Included)