Wolf Tooth Precision Headsets for Trek Knock Block are machined in the USA out of aircraft grade aluminum with superior sealing for protection against the elements. Available in a variety of colors to add some style to your bike. These upper headsets are for Trek frames with molded-in internal bearing cups.

– Designed to work with Trek’s Knock Block system
– The top cap on these headsets have unique raised features that key to Knock Block compatible stems (made by Bontrager
– If spacers are needed, you will need to use special Knock Block compatible spacers with notch features
– This product is the upper headset only
– Lower headsets on bikes with Knock Block do not have any unique features. They are usually IS headsets which are available separately