FeaturesErgonomically designed grip fits the contour of the hand, rear upper extension supports the web of the handGrip surface has the texture and feel of rubber with the strength of a rigid gripGrip includes gapperAn ergonomic grip with an extension that fills the web of the hand for more comfort and better recoil control. Slight hint of finger groves for a positive feel and the width is tapered from top to bottom. Mounting hardware not included. The Gapper fills the gap between the trigger guard and the pistol grip on the ARM4 and cushions your knuckle, prevents abrasion to your finger and provides a more finished look to your rifle. The Gapper is made from solvent resistant Santoprene, clips in easily, and secures with a tight friction fit.