Eachbid Crank Bottom Bracket Plug Arm Installation Tool For Shimano HollowTech II Will fit the end cap on Hollowtech II cranks. Used to preload the bearing tension on Hollowtech II (outboard bearing) cranks & bottom brackets. Size:4cm x 4cm . Package Included: 1 x Shimano Installation Tool NO Retail Box. Packed Safely in Bubble Bag.