Our Centerlock Lock Ring Tool looks a lot like our 16-notch bottom bracket tool because it is our bottom bracket tool. The most common "external" lock rings for centerlock disc rotors have 16 notches and an OD of 44mm. The open design of the RWC wrench takes the guesswork out of proper tool engagement and allows for any length of protruding hub axle to pass right through the tool (unlike many socket-type versions). The crowfoot design with offset 3/8-inch socket drive allows for use of a proper torque wrench (set tool at 90-degrees in relation to the wrench). Made in USA.