High grade KT88 limited edition tubes, believed to pre-date the Shuguang “Treasure” series. Features include: 300B style glass, Ceramic base, gold plated pins, double top getter with separation mica. Please note although they are labelled KT90 they are KT88. We can remove the print if requested. AVO matching and audio testing add £2.50 per tube. Excellent all round sound, test well and good reliability.