Matched Quad Shuguang Kt88-t Premium Vacuum Tube Nature Sound High-end Gift Box This series is the important product after the Shuguang Treasure series (Very famous black glass valves).It is based on Shuguang Treasure serie, and absorbing the advantages of the global outstanding tube, gone through upgrading and renovation for three years. The materials is very particular for this series, Including Japanese Toshiba Thoriated tungsten filament (electron emission stability, long life),German high-density carbon anode, High-purity high-density vacuum smelting graphite, Platinum gate, High transparent lead-free glass. Nature Sound series of pin and socket are all gold plated (24K), and can withstand the test of Salt experimental years without fading, will not fade, good electrical properties. All production processes, handled by the staffs, which have 30 years of work experience. All tubes has been rigorously tested and precision matching before leaving the factory. Package Included: 2pcsShuGuang Nature Sound series KT88-T Vacuum Tube in Gift Box Matched pair