2PCS Dual Male Quick Disconnect Adapter Stainless Steel Double Male Quick
2PCS Dual Male Quick Disconnect Adapter Stainless Steel Double Male Quick-Disconnect Coupling Adapter for Air Fill Station Tool Fittings, Universal Fill Nipple. This is useful if you are trying to transfer air from a large bottle to a smaller, more portable bottle, fill a SCBA tank, transfer air from a tank to a PCP airsoft or paintball gun.