29mm open bore adaptor is used to press 29mm x 42mm (DUB) sealed bearings. The adaptor is machined with one step at 29mm OD, which fits into the center of the sealed bearing. Will press in Wheels Mfg SRAM DUB-compatible bottom bracket cups. For use with Wheels Mfg Bottom Bracket Press (PRESS-7, PRESS-7-PRO or PRESS-9-PRO) Installs: 29X42 (DUB) bearing Inner Step Outer Diameter: 41.8mm Outer Diameter: 28.9mm Thru Hole Diameter: 12.8mm (1/2) Thickness: 7mm Compatible with PRESS-7, PRESS-7-PRO or PRESS-9-PRO handles/rod Machined, red anodized aluminum