These Hellfire shock pistons are precision machined from aerospace POM (polyoxymethylene). Harder for precise internal shock movement and less friction for smoother suspension movement. The 1.6mmX2 hole size is recommended for the front shocks of the Hellfire.

POM (polyoxymethylene) is an advanced, aerospace polymer material that is extremely durable, lightweight and strong, providing the perfect mix of characteristics that make it ideal for racing applications! Color: White See page 25 in Hellfire Instruction Manual