Used to install and remove 16-notch external bottom bracket cups, the 1609/2HOBBY-US is perfect for the home mechanic. The precision manufacturing ensures that it's a good fit and when used properly won't mar your bottom bracket finish. The wrench is compatible with most Shimano, SRAM, FSA, Campagnolo, etc. bottom brackets, anything that uses a 16-notch design for the most part. It also can be used with Shimano Centerlock disc rotor lock rings with external splines, such as those found on 15mm & 20mm thru-axle hubs.