Kink bottom bracket kits include precision sealed bearings, machined dust cover cones, and all the spacers needed for perfect crank and chain alignment. The center tube spacer is a standard 51mm width so no additional internal spacers are needed, and on the off chance your frame requires a 48mm center spacer, it can be cut down using the cut guide machined into the spacer.Specifications:- Sizes: 19mm- Type: Mid- Material: 6061-T6 Aluminum- Bearings: Precision Sealed- Weight: 5.0oz