Riverstone Audio - Matched Pair (2 Tubes) 9-Pin GE NOS/NIB JAN 5670W Fully-Tested Vacuum Tubes 6N3, 6N3P, 2C51 5670 396A Tube Upgrade/Replacement - 5670W Platinum Grade Pair Closely matched Pair (2 tubes) of GE JAN 5670W Vacuum / Electron Tubes. These vintage 9-Pin tubes and are generally equivalent to 6N3, 6N3P, 6N3P-E, 2C51 and 396A tubes. PLEASE NOTE: 5670W tubes can only be used to replace 6N3, 6N3P / 6N3P / 2C51, 5670 and 396A tubes - DO NOT substitute for any other type of 9-pin tube. Vintage Mil-Spec Vacuum Tubes. All Platinum Grade vacuum tubes sold by Riverstone Audio are guaranteed to test at NOS (new old stock) levels. All 5670W vacuum tubes sold by Riverstone Audio are tested and matched using an Amplitrex AT1000 tube tester. AMPLIFIER DAMAGE CAN OCCUR IF YOU SUBSTITUTE THE WRONG TYPE OF TUBE - BEFORE ORDERING VERIFY the type of tube (printed on the tube) that is used in your amplifier and if 5670W is a suitable substitute - if any doubt exists regarding tube replacements contact the manufacturer of your amplifier.**