Benjamin & Airforce PCP HPA Hand Pump Rebuild Reseal Seal O-Ring Kit 90 durometer o-rings for the Benjamin and Airforce PCP Hand Pump Rebuilding the pump is fairly easy and can be tackled by anyone with basic tools. Instructions are available at Sun Optic's website (the mfg of both pumps): http://sunopticsusa.com/pump-instructions Video tutorials are available on all the common sites. Unlike other sellers, my parcels will always have a tracking number.