Mixer pressure balance kit</br>O-ring included</br>Parts GP500520 and GT77759 in kit</br>Genuine Kohler part</br></br>Product Description</br></br>You can count on genuine Kohler parts to maintain the same Kohler quality. Includes GP500520 and GP77759.</br><br/>http://www.amazon.com/gp/product/B001GZU9FY