Steel. This product is made of high quality steel, which is stamped and riveted through multiple processes. The material of the hook is 65Mn of Beijing Shougang, which ensures the mechanical strength and availability of the hook. Reasonable price, environmental protection and pollution-free, is the ideal product of balance block. 1. Model: 5g, 10g, 15g, 20g, 25g, 30g, 35g, 40g, 45g, 50g, 55g, 60g, 70g, 80g, 90g, 100g? 2. The hook is 65Mn spring steels of Beijing first steel, which ensures the elasticity and removability of the hook? 3. The error of gram weight shall not exceed 5%, which meets the national standard.