Liftmaster/Chamberlain/Sentex 41A5434-11A Garage Door Openers Full belt assembly for use with Liftmaster/Chamberlain/Sentex belt drive models 2500, 2580, 2280, 3500, 3580, 3280 Full belt assembly for use with chamberlain belt drive models WD822k, WD922k, WD912k For standard 7 foot high garage doors Belt length end to end 233 1/2