LIFTMASTER Garage Door Openers 41A5250-1 Belt 8' Door Full belt assembly For use with Chamberlain belt drive models WD912KS, WD822KS, WD822KD, WD952KD, WD952KLD, HD600. For standard 8 foot high garage doors. "Square" rail assemblies ONLY. Belt length end to end 260 1/2".