stempel standard stempel 90 100msTokyo Marui standard pistons have been on the market since the first electric rifles. The quality is top notch and can be bent for tunings up to M150. We often use this piston for our tunings as it is durable during normal operation but soft enough that it will break if the slider experiences problems with a ball getting stuck so that the cost is made possible for the customer (a set of gears costs approx. 500, for comparison).