Designed for rough treatment on the job with a cast iron pump head, precision fit plunger and extra heavy follower spring. The length is 21-3/4". The 1 oz. per 33 strokes. Jam proof toggle mechanism prevents binding or accidental beding of plunger . Exclusive "flip over" follower provides a superior seal for either cartridge or bulk loading applications This grease gun has a rugged cast pump head for strength and durability. Tough, resilient and impervious to lubricant. The extra-heavy follower spring insures for positive priming and uninterrupted pumping action. Follower rod locks into follower to force prime. Accessible check valve allows easy cleaning without gun disassembly. This is a one-hand operation with similar of Lincoln lever-type grease guns. Its a first choice of users everywhere.