Sino/Chinese Shuguang KT88 – Billington Gold Triple tested and matched. These are excellent sounding KT-88 from China-GUI GUANG at an EXCELLENT price! Just $49.99 per tube, provided in original boxes. Matched to perfection within 1-3mA. This is a suitable replacement for any 6550/KT-88 tube type. Please enter qty for a matched pair, or qty 4 for a matched quad!