Featuring some of the lowest stack height bearing cover options available, the Cane Creek Hellbender 70 Slam - IS42 4.6mm - Upper Only is a premium headset designed for riders who want to lower their handlebars as much as possible while still maintaining bearing longevity and proper preload. Made with 6061 T-6 Aluminum cups and covers, this headset is both lightweight and strong. The top cover is designed with the lowest stack height possible for both ZS and IS headsets, while the alloy dual-seal crown race provides excellent seal efficiency. The Hellbender 70 Slam also features a low friction carbon-friendly captured compression ring, as well as premium sealed HELLBENDER stainless bearings. With a stack height of just 4.6mm for IS headsets and 2mm for ZS headsets, this headset offers a sleek and streamlined look for your bike. Upgrade your ride with the Cane Creek Hellbender 70 Slam - IS42 4.6mm - Upper Only.