This is a Limbsaver known as the Recoil Pad, model 10101.
The customized LimbSaver's Classic Precision-Fit Recoil Pad is designed to specifically fit a variety of rifles" shotguns" and muzzleloaders" reducing felt recoil by up to 70 percent. The recoil pad enables you to shoot longer without discomfort and bruising" while also helping to increase accuracy of follow-up shots and provide improved control for maximum stability. It's made from LimbSaver's proprietary NAVCOM technology (Noise and Vibration Control Material)" which effectively absorbs a wide range of frequencies to dissipate energy and vibration.
Features:
Fits Rem. 700 ADL/BDL ML 710 7600 870 (1216) 1100 (1216) 11-87 (Syn.) SP-10 Marlin XS7 9 (Syn.)
Incorporates muzzle jump technology