The very popular blue SHS Piston - 15 Carbon Steel Teeth - For the price, you cannot beat this airsoft piston. It takes an incredible amount of punishment and keeps on going. Whether you need a replacement for your broken stock piston, you need something that can handle your high rate of fire, or you're looking for a piston that can handle the stress of 500+ FPS, the SHS 15 steel teeth piston is right for the job. Because this piston has a full rack of steel teeth, it is also ideal for short-stroked, high rate of fire guns. It is compatible with almost any version gear box (Versions 2, 3, 6, 7, etc.). The first tooth is slightly lowered to decrease the chance of pre-engagement by the sector gear. A great part to replace your JG, Echo, Marui, or other factory component in your gun currently.*please note, this is the newest 2014 version with reinforced thicker steel teeth. (please note: packaging may be generic or labeled as 'Rocket Airsoft', but is made by SHS OEM)