Bike Bicycle Crank Extractor Wheel Puller Bottom Bracket Repair Tool This tool is used to remove Square type crank arms, all you need is either a 5/8 or 16 mm spanner or just an adjustable spanner: First, remove the bolt in the crank arm. Second, screw the lower back part of the tool into the crank till tight. Third, screw in and continue to tighten the silver piece of the tool until the crank starts to move. Bottom Bracket Remover Fits for any brand type bottom bracket. Suitable for any 20 teeth splined type bottom bracket, generally the type used for any bike. The tool can be used with either a 24mm socket, wrench or an adjustable spanner. Package Includes: 1 X Crank Extractor 1 X Bottom Bracket Remover