The Hyskore Black Gun Machine rest progressively absorbs the recoil pulse by employing two long (110mm) stroke nitrogen filled compression dampers assisted by adjustable coil springs. This gives it the unique ability to handle everything from .22 LR to .375 H&H. In addition, the dual rail design accommodates pistol grips and high capacity magazines. The gun can be fired from the shoulder, using the strap, directly off the shoulder without the strap, or with the strap and secured in the vise for repeatability testing. The entire vise assembly can be removed to expose a platform for rest bags and a remote hydraulic trigger release is included with the set.WARNING – This product can expose you to chemicals including Propolene Glycol, which are known to the State of California to cause cancer and birth defects or other reproductive harm. For more information go to www.P65Warnings.ca.gov.