Weihrauch HW35-HW80 conversion kit. Includes Vortek VacSeal30. Converts HW35 and HW80 older airguns with leather seals to be able to switch from leather to a high performance Vortek VacSEAL30 or use of OEM nylon seal. No sizing required for most older 30mm compression tubes. IE: HW35 and HW 80. Easily increase the over-all shot cycle of your older 30mm air gun performance simply by replacing the old leather seal with this adapter and synthedic seal. Our Leather Seal Replacement threads direct onto the M8 threaded piston. We have had report calculations of 3-5% increase in performance with a smoother shot cycle.NOTE: very important to check for scratches and burrs in the cylinder of older airguns used with leather seals.