Factory Hatsan and Walther air rifle seals are known to suffer from low-quality materials that degrade quickly under intense spring or nitro-piston compression cycles. Our Australian-made polyurethane piston washers provide superior resistance to abrasion, tearing, and mechanical pressure. By sizing the sealing edge slightly larger than standard factory specs, these seals adapt flawlessly to cylinder imperfections, sealing away micro air gaps and increasing power output.