More upgrade products from X-Fire/PDI... "Made of Stainless steel. The palsonite is a metal finishing. Through this process,the surface will be more rigid & be black. The shape is type of Remington cause that's suitable for ­the hand. You'll need to buy the Ball & Springs for PDI APS-2 or M24 & M24X Handle.This is also available for CA M24 but not for CAW M24.  We design precise spring & ball as more surely click with your rifle. 1 package is included 4springs & 4balls.Each 1 are spare."