This 8-piece kit contains two 0.5 ounce pieces, two 0.25 ounce pieces, and four 0.15 ounce pieces of tungsten weights. This Incremental Weight Kit makes adding a lot of weight to your roller derby car as easy as drilling a hole thanks to tungsten's density, which is 1.7 times greater than lead and more than 2 times greater than zinc. Drilling a 25/64′′ hole in the body at the proper weighting location makes installing these weights simple!