material: premium flex plus carbon steel
surface finish: chrome plated according to ISO 1456:2009
Tool also fits the disc brake rotor nuts with 16 external notches.

How to use the tool:
The open bottom bracket wrench is used to remove and install Shimano Hollowtech II, Campagnolo Ultra-Torque and Power Torque, Race Face, FSA, SRAM, Truvativ, Chris King bottom brackets as well as many and others. The 1609/2HOBBY wrench also fits on the external centerlock disc nut.