fat bike rear hub, Disc Brake, Freewheel type. 195mm o.l.d. 3/8" 36 hole all steel. Hello, this hub is a very good replacement for 26" x 4" and 20"x4" fat bikes. The bearings are ball and cup design and are factory torqued! They feel tight when new, but will break-in GREAT!!! We have used them many times for customers with very reliable results. Please check the measurements in photos to ensure proper fit. 🇺🇲 All our parts are inspected, packed, and shipped in the USA. We love testing products. https://youtu.be/SSz2Y7xhQmc Thank you Sincerely Dennis Record