These weights mount on the inside channel of the MDT ACC Chassis forend. With the maximum forend capacity of 5 weights, they add 1180 grams to your ACC chassis system. The interior forend weights can be added and removed without removing your barreled action, simply remove the forend cap, slide them into the desired location under the barrel, and screw them in place from the bottom. Package of 5 weights, 236 grams each.