Wheels Manufacturing Bottom Bracket Spacer Pack Description: This Wheels Manufacturing Bottom Bracket Spacer Pack includes bottom bracket cup and spindle spacers for adjusting chainline or bearing play on various bottom bracket shell types. Note: When used with a Wheels Manufacturing GXP compatible bottom bracket, adding cup spacers between the non-drive side cup and the frame will move the chainrings on a GXP crank closer to the frame (reducing the chainline). For Specialized road frames with the 61mm wide Carbon OSBB shell, you would place 3.5mm of spacers between each cup to effectively widen the BB shell to 68mm when used with non-Specialized cranks. One bag will properly space one 61mm wide Specialized OSBB shell to 68mm. Features: Bottom bracket spacers, perfect for protecting frames or perfecting chainline Machined from 6061 aluminum and anodized black Compatible with any 46mm ID BB shell: PF30, Specialized Carbon OSBB, 386EVO, 392EVO, BBRIGHT Includes: (2) - 2.5mm bottom bracket cup spacers (46mm ID) (4) - 1.0mm bottom bracket cup spacers (46mm ID) Specifications: Color: Black Inside Diameter: 46.20mm Outside Diameter: 52.00mm