Durable 20-g stainless-steel slotted mass. Use as an addition, spare, or replacement for the Eisco® Stainless-Steel Mass Set (item #751438, not included) and the Eisco® Stainless-Steel Slotted Mass Hanger (item #751421, not included). Size, about 21 mm diam x 8 mm H. Solid stainless steel.