CNC-machined from a premium nickel chromoly steel (8620), case-hardened and finished with an electroless nickel plating for corrosion/wear resistance and lubricity Sprockets are drilled and tapped to accommodate late-model lock plate Offset measurement is taken from the face that rests against the mainshaft bearing to the inside of the teeth for “Total Offset” description For use with .530 pitch chain Made in the U.S.A. Note : 86'-93' Big Twin models & 91'-93' Sportsters require use of OEM #33344-94 (spacer), OEM #12067A (seal) and OEM #11165 (O-ring)! We stock them all! Don't see the size you need or need help with what offset? Give us a call at 602-788-0364 or email [email protected]