Check the listing for details. Wolf Tooth Premium Internal Headset - EC44 Upper / EC44 Lower, For Enve. Condition: New. Listed at 219.95 USD. Wolf Tooth Premium Internal EC44 Headsets were developed for frames using the ENVE IN-Route System of cable integration with a 44mm head tube. It was made for cyclists who want a clean, aero cockpit that keeps cables and brake lines out of sight. Wolf Tooth headsets are machined with aircraft-grade 6061 aluminum at Wolf Tooth in Minnesota, USA.Designed for the ENVE IN-Route System with a 44mm straight headtube and a 1-1/8” to 1.5” tapered steerer tube (FITS ONLY ENVE In-Route System). This Internal headset helps reduce aerodynamic drag by hiding cables away from airflow, and presents a svelte profile with its ultra-low 15.8mm upper and 12.25mm lower stack height. Features Wolf Tooth's best-in-class triple-sealed system to protect the premium Enduro stainless steel bearings from the.