Check the listing for details. FSA Headset Assembly for TREK Knock Block Tapered 1-1/8" - 1-1/2" ( 1.5" ) 58-De. Condition: New. Listed at 59.99 USD. FSA Headset Assembly for TREK Knock Block Tapered 1-1/8" - 1-1/2" ( 1.5" ) 58-Degrees FSA Headset Assembly for TREK Knock Block (for Tapered Fork Steerer 58-Degrees ) - Fits Fork Steerer OD: Tapered 1-1/8" Top to 1-1/2" (1.5") Bottom - Integrated Headset Fits 1-1/8" to 1.5" E2 Bicycle Headtube with Knock Block - Color: Black - Stock Chamfer 36 inner/45 outer on both upper and lower bearings - Top cap and stem spacers are Not included with this kit - Qty. 1 FSA Integrated E2 IS Knock Block Headset Assembly, 1.5" crown race is included (Includes items in listing photo) - MFR # : IS-2-HBS/42/ACB - For use as replacement headset for Trek Part # W543168 or 5252156- Replaces Trek 2017-2020 Knock Block Headsets - Please visit our store for a variety of Road and Mountain Bike Headsets! Powered by Solid Commerce The All-in-One Listing, Inventory & Order Management Solution for Online MerchantseBay integration by