Clutch housings are often overlooked when looking for extra power. Light weight housings allow for quicker acceleration and more efficient cooling. This housing is a perfect upgrade for any bike, stock or dragster! Through constant research NCY continues to bring design concepts to the CVT transmission that are unmatched by any others. *Textured for better initial bite *Cross drilled for heat dispersion and debris extraction. *Ultra efficient cooling properties. For use on most Yamaha engines from 50-100cc 112mm inner diameter. Suitable for 107mm clutch.