Tungsten Cylinders - 1/8oz eachDerby Monkey 1/8oz Tungsten Cylinders are 3/8″ (9.8mm) in diameter x 2.7mm in length. These Tungsten cylinders are made specifically for Pinewood Derby cars and has its own alloy formula to weigh more than other tungsten cylinders. Just drill holes in your car body with our 3/8" drill bit and glue in the weights.You get a total of 8 cylinders for a total of 1oz.Tungsten is the world's 4th heaviest metal. It weighs up to 1.8x as much as lead and over 3x the weight of the Zinc/Pewter weights. This is the perfect weight for Pinewood Derby Cars.Tungsten is a safe non-toxic metal and it takes up less space in your car. Less space, means more weight concentration in the CG area, faster building time and more speed on the track.