Sunshine Serafina High Quality Sturdy and Durable Nickel Plated Flat Sided split Key rings Key chains Keys Holder 36pcs (silver) Size: 30mm(outside diameters) * 25mm(inside diameters) Net weight: about 190g / set Lightweight and sturdy High-security connection and attachment for keys and other important items. The spring tension is firm enough that keys don't slip out and also soft enough to make putting items on reasonably easy.