Places the thumb closer to the centerline of the bore; gives greater leverage and recoil control for shooters that use a high thumb hold. For shooters with smaller hands, the lower position is easier to reach and deactivate. Serrations on thumb pad help ensure positive thumb engagement. Contact pad is 1.9″ (2.8cm) long and .314 (8mm) wide. We recommend that this product be installed by a competent gunsmith. No liability is expressed or implied for damage or injury, which may result from improper installation or use of this product. Installation of these parts may nullify the warranty of the firearm manufacturer.