Wheels Manufacturing's GXP-LEFT open bore adapter is used to press 22x37x8 sealed bearings in to bottom bracket cups and direct fit frames like TREK BB90. The adapter is machined with one step at 22mm OD, which fits in to the center of the sealed bearing. Features: Use with 22X37X8 (GXP) bearing Outer Diameter: 37mm Inner Step Diameter: 22mm Compatible with PRESS-1 or PRESS-4 handles Machined, anodized red aluminum Sold individually