Replacement Weihrauch Piston Seal in Plastic for models: HW30, WH70 Replacement 25mm OD Piston Seal / Washer for Weihrauch made Air Rifles, If your Piston seal is split or worn, then the compression chamber will lose pressure past the piston, lowering the power and accuracy of the Rifle. It is recommended to change the Piston Seal / Washer either when reduced power is noticed, or if the spring is replaced. External diameter: 25mm
