Mini Pistol Grip Grease Gun with 4" Steel Extension and 4 Jaw Coupler Cartridge Capacity: 3 oz. Bulk Capacity: 4 oz. Stroke Delivery: .6 oz. / 40 strokes Maximum Pressure 3,500 PSI Features: one-hand pistol grip operating mechanism, non-slip powder coated barrel, and a unique aluminum die cast head with two discharge ports - the commonly used front port and a top port which can be used in case of clearance issues