Check the listing for details. Enduro HDK-0013 Drop-In Tapered Headset Kit with Angular Contact Bearings &. Color: Black, Condition: New. Listed at 131.73 USD. This Enduro Integrated/Drop-In headset for 1-1/8" x 1-1/2" tapered fork steerer tubes features Angular Contact Bearings with chamfers, premium 440C balls and races, and 90% fill with high-pressure waterproof grease. This top quality Drop-In headset is built for long-lasting durability thanks in part to the high performance bearings that are guaranteed for as long as you own the bike.This IS41/IS52 Integrated/Drop-In headset fits bikes with head tubes with 41mm top IDs and 52mm bottom IDs, bearings with 36°/45° chamfers, and tapered (1-1/8" x 1-1/2”) steerer forks. Features top-quality 440C balls and races, dual-lip seals top and bottom, 90% fill with high-pressure waterproof grease, and are guaranteed for as long as you own the bike. Upper 1-1/8” bearing ACB 3645 SS (also known as.