Tool-less Buttpad Height Mechanism: With this assembly, you can add tool-less buttpad height and cant functionality to some KRG chassis that did not come with it already. With the tool-less adjustment, it's easy to lower the buttpad to get a cleaning rod down the bore or to adjust the buttpad when transitioning between different shooting positions such as seated to prone for example. The buttpad mount plate is upgraded to the Whiskey-3 version which has ample set positions for height plus positions for 15 degrees of cant each way. Fits: The following KRG chassis (each chassis has its own version of the mechanism): X-ray, Bravo, 180-Alpha Restrictions: Does not come with new buttpad, use your existing buttpad