ITEM NAME:1pc crank bottom bracket plug arm installation tool for hollowtech lj Description: 100% brand new and high quality Features: Will fit the end cap on Hollowtech II crankset Used to preload the bearing tension of Hollowtech II (outboard bearing) cranks & bottom brackets Size:4cm x 4cm Package Includes: 1 x Installation Tool note:.Will fit the end cap on Hollowtech II crankset. Used to preload the bearing tension of Hollowtech II (outboard bearing) cranks & bottom brackets. 1 x Installation Tool.