The AutoLock gate features a patented latch that allows rapid pass through in either direction. Simply pull and twist the latch to open and close just swing the gate shut. Our AutoLock gate is constructed of aluminum which is lighter weight than steel and virtually rustproof. 10.5 extension (Model BX1) is available for openings 40 to 50.5 21.75 extension (Model BX2) is available for openings 40 to 61.75