Designed for use in Modular Driven Technologies' ESS, ACC and SRS V5 rifle chassis, the MDT ACC Chassis Buttstock Weight is made entirely of steel and adds 0.65 pounds to the rear of the rifle, adding weight and adjusting the balance point rearward on the gun. To install the MDT ACC Chassis Buttstock Weight, users can simply remove the buttpad on their rifle chassis, slide in the weight and secure it with the included screws, then replace the buttpad. The weight will also slide into the company's second-generation ESS folding stock, but it will not fit in any other manufacturer's stock. Mfg: Mdt