Zeta (ZETA) steering stem cap Red ZE58-4133 Aluminum stem shaft cap keeps dirt and mud out to prevent rust inside of the stem shaft Made of A7009-T6 aluminum and light weight design Available in titanium, black, blue and red anodized colors with cool laser print Zeta logo Leaf springs hold inside of stem shaft and wont come off even in hard riding Fits shaft inner diameter from 13mm to 17.5mm, fits almost all of dirt, supermoto and dual sport bikes