Male quick-disconnect fitting with male M13x1 threads and o-ring Converts Seneca, Sam Yang, Sumatra & Career rifles to connect to the Benjamin and Air Force 3-stage hand pumps Connects to female quick-disconnect (AV-00043), which has male 1/8 BSPP threads & fits most scuba tank & hand pump adapter hoses Installation instructions: THERE IS NO NEED TO RELEASE THE AIR PRESSURE FROM THE RESERVOIR. To start the old fill port turning, insert the round shaft of a punch or screwdriver into the fill port hole and turn the port counterclockwise. Once the port loosens, you can take it off by hand the rest of the way. After you've unscrewed your old fill port from the end of your tank, place the new o-ring in the female thread on the gun and thread in this quick-disconnect fitting. Tighten well to seal the connection. No need to depressurize the tank because the tank has a check valve.