Genuine LiftMaster K16-3L320 drive belt, size 3L320, for the SW420 and SW420GL commercial swing gate operators.
Fitment: LiftMaster SW420 and SW420GL. Runs between the K17-G0475 6-inch pulley and the motor pulley in the D drive kit.
Replace when the belt is glazed, cracked or slipping under load. Check the pulleys for wear at the same time.
