Buy the (11) 15-50B12LGH 50B12 1" X 1/4" 2SS 5/16 SPROCKET at North Shore Commercial Door. We offer excellent customer service, fast shipping, and great selection. Can't find what you're looking for? Call us! If this part number doesn't match up to yours don't worry! This item was known as part numbers K15-50B12LGH, 15-9020, 15-50B12LGF, 159020, 112-00020, and G159020 in the past.