The Weihrauch MainSpring fits the air rifle models: HW35, HW77, HW80, HW80K, HW95K, HW97K, HW98 and HW99

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.