Manufacturer: SHS Material: Nylon Fiber All Steel Teeth Reinforced AEG Piston For ARMY R85 or Other Compatible L85 Series Airsoft AEGs SHS manufactures a variety of pistons. From their full steel teeth pistons for your high torque setups to the standard 1 steel tooth piston to the creative lightweight piston for a boost in ROF, you'll find the piston your looking for made by SHS. All of them utilize nylon instead of polycarbonate for the piston material. This produces a a tough yet still elastic piston. For the unlikely event of one of your steel teeth breaking, SHS makes replacement steel teeth for most of their pistons.