4th gen hill pcp pump with dry pack. Latest 4th generation design features. 1. Less effort, we have made the Mk4 pump even easier to pump. 2. High volume, we have kept the highest volume output so less pumping. 3. Field service, you can strip the pump in the field quickly with few tools. 4. Hill warranty, each pump carries the hill limited lifetime warranty. 5. Using the patented, hill dry pack gives 90% dry air, great for your gun. 6. New longer more flexible hose. Pump comes with hose with 1/8 inch bsp connection. Some air guns may require additional adaptors.