Features 1、Come with strong thermal diffusion ability, because of adopting lightweight high‑silicon aluminum alloy 2、Possess a good thermal fit to the piston and reduces the weight of the whole machine, the thermal conductivity is increased by 42% compared with the bimetal structure 3、Made of one‑piece forming, increase the strength of the machine body and improve the surface hardness, more durable 4、The product has been improved wear resistance, corrosion resistance and high temperature impact resistance greatly 5、Possess surging power, strong gas compression ability, clear thread and smooth knob, not easy to jam Specification Item Type: Cylinder Piston Kit Material: High silicon aluminum alloy Cylinder Diameter: Approx. 43mm / 1.7in Package List 1 x Cylinder 1 x Piston 1 x Piston Circle 2 x Piston Ring 1 x Piston Pin