**REPLACED BY THE LJ8950W *** LiftMaster 3950 jackshaft operator is designed for use only on a commercial rolling sheet door application. It can mount on either the right or left side. Maximum door height is 12 feet. Maximum door width is 14 feet. Maximum door weight is 650 lbs. This operator comes complete with the necessary mounting and sprocket hardware for installation on either live or dead shaft rolling sheet doors, as well as photo-sensors to insure safe operation. The Heavy-duty 24V DC motor provides ultra-quiet operation, along with variable speed smooth start and stop.