BrassCraft WB034-15N 3/4" FIP x 3/4" Nominal Male/Female Sweat x 15" Copper Water Heater Connector (7/8" O.D) Corrugated copper tube 7/8" O.D. x 15" L End connections: 3/4" FIP x 3/4" nominal male/ female sweat (7/8" I.D.) Requires less torque to seal with a pliable nitrile rubber washer, especially on rough nipple surfaces