Die cast pump heads for strength and durability. Knurled barrel for a non-slip grip. Convenient one hand operation. Uses standard 14 oz grease cartridges or can be bulk filled. Locking plunger mechanism holds follower rod firmly in place for easy cartridge replacement. Premium heavy duty model. Working pressure: 4,500 psi, develops up to 10,000 psi. Includes 16 inch flexible hose, coupler and air release valve. Variable stroke feature.