Double-sided socket tool for installing and removing both 48.5mm and 44mm 16-notch bottom bracket cups. Compatible with all Wheels Manufacturing bottom brackets. Socket is machined for 1/2" drive, but a 3/8" to 1/2" adapter is included so you can use it with 3/8" drive torque wrenches. 48.5mm, 16-notch pattern matches up with Wheels Mfg bottom brackets, along with some FSA MegaEVO bottom brackets. The 44mm, 16-notch side matches up with Wheels Manufacturing bottom brackets, along with many other outboard bearing bottom brackets including Shimano, FSA MegaEXO, Campagnolo Ultra Torque and SRAM/Truvativ. - Machined 6061 Aluminum - Anodized Red