Brand new, factory matched Quad (4) Genalex KT-88/6550. The Genalex KT-88 is considered by many to be the finest of all Kt-88s made today. Finding these tubes at a reasonable price is next to impossible, and this is a way to get an excellent value on these wonderful tubes, especially if you need current matched tubes for your amplifier.These are factory tested at real world operating voltages and matched for current and transconductance. You will not be disappointed in the performance of these tubes.They are burned in for 24 hours and then platinum matched by the factory at 400V plate, 225V screen and -19.1V bias. Insist on factory platinum matched tubes for best performance.They are shipped in factory retail boxes and labelled with factory matching statistics as shown.All tubes carry the 90 day factory warranty against defects from date of purchase.Please email with questions and visit my many other tube sales! Compare these tubes to sets costing $190 and up. I have been selling vacuum tubes for more than ten years, please buy with confidence.