Mini Hand Operated Air Pump High Pressure Compressor 300bar 30mpa 4500psi. Work more than 2 hours below 300bar. Liquid cool down, reduce core temperature. High-pressure piston head core: pressurized design, can reach the role of self-compensation after wear. Copper unidirectional valve: durable, failure rate is low. Quick connector: 8mm fast female head. Tire fittings: American/English tire connector. 1 x Set of Hand Operated Air Pump. If you are not 100% satisfied, please let us know the Detailed Problem, We will give you a 100% satisfactory solution. You brought wrong size or wrong item. Communication is the best way to solve problem. Our goal is to make sure you are a happy customer and pleasant shopping with us.