Primary Chain Adjuster. Fits Sportster 1977-1990.

Features & Benefits:-

* Reduction in vibration

* Constant and correct tension at all times

* Smoother shifting

* Extends the life of your primary chain

Tech Tips:-

* Not necessary to remove the primary chain for installation

* Replaces OEM # 39966-80

Proudly made in the USA!

MFR PART No: M6-XL4

ROLLIES PART No: HAY-M6-XL4