Zinc plated heavy duty swivel hook block, forged hook, no latch with 3-1/2" diameter double sheave grooved for 5/16" cable. Equipped with oil impregnated bronze bushings for longer service life. We recommend oiling the bushings occasionally if subjected to heavy use. Working Load Limit: 1550 lbs. Weight: 5.5 lbs. Ultimate block strength is 4 times the working load limit.