Fits all 16-notch x 44mm external bearing bottom bracket cups and updated design also fits 16-notch x 44mm disc brake lockrings Updated design features a square 3/8` drive - Also works with Pedro`s snap-channel Pro Socket Handle, 24mm socket or wrench, or in a bench vise Professional quality, precision sized for the perfect fit External BB Socket 16-Notch 44mm 6460261 3/8`UPC/EAN/GTIN: 790983296957