This 29mm open bore adapter is used to press 29mm x 42mm (DUB) sealed bearings. The adapter is machined with one step at 29mm OD, which fits into the center of the sealed bearing. For use with Wheels Mfg. bottom bracket press (PRESS-7 , PRESS-7-PRO or PRESS-9-PRO). - Inner step outer diameter: 28.9mm - Outer diameter: 41.8mm - Thru hole diameter: 12.8mm (1/2-inch) - Thickness: 7mm - Machined, red anodized aluminum - Sold individually