The Box Three BMX chain is polished and then chemically treated to achieve corrosion resistance. All Box Three chains have chamfered shifting edges, solid plates and solid pins to safeguard durability. Our unique inner link spacing is engineered to grab those modern wide/narrow chainrings. They are compatible with BMX 3/32" and 1/8" chainrings and cogs which fits most retro-modern 29 inch BMX bikes and smaller bikes.