MACE CASE NEEDLE BEARING SET TO SUIT HOLDEN L67 SUPERCHARGED 3.8L V6These needle roller bearings are the closed cup style. They are located in the rear of the supercharger main housing. Over time, the factory counter parts wear out and lose their grease retention properties leading to a noisy rotor pack. Our aftermarket replacements come pre greased, ready to go. Specifications: ID: 17mm OD: 23. 8mm Height: 20. 4mm Vehicle Fitment Guide Note: Installation services are available, please contact us for further details.