New for 2020, we think the A800 is the best waist chain of this type on the market. The machined steel Martin link is the correct thickness to fill the entire slot when used with a black box or blue box. While some martin links are thinner and rattle around, this one will fit perfectly. When used without a black or blue box, just wrap around subject's waist, insert Martin link through any link of chain at the appropriate tightness, and thread handcuffs through link to form a secure and easy-to-use waist restraint. 72" long with snap clip at end to tie off excess chain. The chain and link are completely nickel plated for durability and rust resistance.