The BPW Bottom Bracket Set is designed for small diameter 1-piece cranks with an outer diameter of 43.1. It is compatible with models OPC 2165 and 2167 and fits chainrings 2026 and 2027. The set features a durable silver finish that enhances both the look and longevity of your bike. It is easy to install and maintain, making it an essential upgrade for cyclists looking for improved efficiency and durability.