Set of 16 titaniun retainers that are a direct replacement for the original steel retainers on:
ZXR 750 / ZX7R from 1991 to 2003
ZX9R from 94 to 2003 (all years)
 
Made of best grade titanium - Grade 5.

The original retainers weight 9,0g and the titanium retainers weight 5,0g, 45% lighter.

These retainers have a smaller profile/height (less 0,5mm) to allow for more valve lift without contact with oil seal and without requiring valve guide modifications.

Using lightweight titanium retainers allows for more aggressive camshaft profiles (lift and duration) without losing control of the valve and increased rpm limits - a must for any performance / race engine.