Pair of hi-lift cable drums for setups with up to 164 inches of vertical hi-lift. Model 6375-165 with a 1-inch bore that fits a standard 1-inch torsion shaft. Each drum handles up to 800 pounds and takes up to 1/4-inch cable. Hi-lift drums are what wind the cable on tall commercial or industrial doors where the track goes straight up well past a standard radius. To figure cable length, it's floor to shaft center plus 181 inches, minus door height. Sold as a left and right pair. Verify your shaft size and hi-lift measurement before ordering.