The Weihrauch Piston Seal fits the HW80, HW80K, HW95K, HW35, HW98, HW99, HW77 and HW97K.

Warning - replacing your air rifles mainspring may increase its power making it illegal. Redbeck Shooting Supplies would recommend that you seek manufacturers advice or a professional gunsmith before attempting to alter your rifle, and that you always check your rifles power using an accurate chronograph to ensure you stay within the law.