KickLite - 'Saving Shoulders Since 2008'! Dont let a sore shoulder end your day early! The patented KickLite system is fully integratd and maintaince free providing years of care free use. The mechanical system is built into the stock tube and allows up to 3/4" of rearward movement of grip upon firing. Absorbs a generous 40 - 50% of felt recoil to allow a full day in the field or at the range. Other product features include a recoil absorbing butt pad to further dampen recoil and provide a solid non slip engagement to shoulder. ** LONG ARM BALL END ALLEN WRENCH REQUIRED FOR INSTALLATION Made in USA - Guaranteed for Life! FITS: 20 GA MOSSBERG 500, 590, 835 KickLite Recoil Absorbing System,40 - 50% Recoil Reduction, 6 position Tactical Stock, LOP adjustments 10.5" - 14.75"Pistol Grip Stock, Shot Shell Carrier Included - Direct Mount to stock, Installation hardware, Lifetime Warranty.