Aeroflow Fabricated Rocker Covers are made completely from exceptional quality aluminum and are lightweight. They have a one-piece billet rail CNC machined from 6061-T6 to guarantee a precision flat surface for superior sealing. They come in either raw or black anodized finished. The covers come with a female -8 ORB for breather applications and a threaded o-ringed billet oil filler cap. All covers are tall enough to clear 99% of rocker combinations.