The general purpose weight includes nine weights. This set includes one each of 10g, 50g, 100g, two each of 20g, and 200g, (all made of plated brass) and one each of 500g and 1000g (both made of cast iron, enamel finish). Each weight has one hook on top and one hook at the bottom. The bottom hook hides in a cavity under each hook. You will be able to hang hooks to each other if needed. Each weight also has This set is perfect for general science and physics laboratory work.
The holder is made of hard plastic.