Campbell® Shell Block, Triple Regular, series: 3003G, Manila Rope Cable, 1/2 in Maximum Cable, 1800 lb, 2-1/4 in Sheave Outside dia, 3/8 in Sheave Inside dia, Self-Lubricating Bronze Bushing Bearing, Metal Sheave, 5/8 in Sheave Width. Campbell® 7208534 3003G Triple Regular Shell Block, Manila Rope Cable, 1/2 in, 1800 lb Load, 3/8 in ID x 2-1/4 in OD