Check the listing for details. Wolf Tooth Premium EC Headset - External Cup, 6061 Aluminum, Sealed Bearings. Condition: New. Listed at 64.95 USD. Wolf Tooth headsets are machined in the USA with aircraft-grade 6061 aluminum. Our headsets have three levels of superior custom sealing to protect bearings from the elements and prolong the life of the headset. They are designed to be lightweight, strong, and durable. Available in a variety of colors. These EC headsets are for frames with external bearing cups, which places the bearing outside of the frame with these headsets. Premium Headsets with Enduro stainless steel bearings have a lifetime warranty on the bearings. Compatibility Stack height designation for EC headsets includes 10mm cup (see tech specs). Any frame that uses an external cup headset with a 34mm upper head tube. inner diameter and 34mm, 44mm, or 49mm lower head tube inner diameter Uppers and lowers sold separately.