Bpv Series Bullet® Piercing Valves Fits O.D. Tubing Size 1/4" 5/16", 3/8" Utilizes The Same Type Of Gasket Found Under The Head Of Most Air Conditioning Compressors. When Installed, The Gasket Compresses The Copper Tubing .020" Creating A Permanent, Leakproof Seal That Will Withstand Any Pressure And Temperature For The Life Of The Unit. Patented Valve Gasket Application Provides 50 Times More Sealing Area Than Competitive "O" Ring Types. A Sealing Force Of Over 180" Lbs., Torque Tested With 500 Lbs., Pressure Tested At 250°F. Precision Piercing Needle Is Engineered For Concentricity And Hardness To Insure Perfect Seating Every Time. Non-Positional - No Adapter Valve Required. Requires Only A 2" Clearance Area For Installation And Operation. Hex Key Wrench Included.