Made of hhcarbon steel material durable and timeproof Standard size suitable for any 20 teeth splined type bottom bracket generally the type used for any bike Crank Extractor is used to remove square type crank arms all you need is either a 5/8 or 16mm spanner or just an adjustable spanner. Suitable for Standard Square Tapers The Bottom Bracket Remover can be used with either a 24mm socket wrench or an adjustable spanner Package Included 1 Bike Crank Extractor Puller 1 Bike Bottom Bracket Remover Removal Tool