Audio Research KT-88 NOS tubes, 8 matched tubes, Amplitrex tested

I have for sale (eight) emissions matched Audio Research labeled KT-88 tubes, These are new old stock tubes and never used or installed in equipment. They all have the same date codes from 2006 as well. The KT-88 output tube is a deluxe version of the 6550 output tube....the KT-88 tube handle more Current and has a higher output. It's a drop in replacement for a 6550 tube plus you gain a few more watts per channel on your amplifier.
The tubes have been tested twice, once 11 years ago from the manufacturer using a vintage Hickok tester and again by me recently using a modern Amplitrex tubes tester. As can be seen in the pictures,the tubes have the test results from the Hickok tester written on the base of the tubes.

Here are the test results using the Amplitrex...the first number is emissions and the second number GM or transconductance
109E/109GM, 108/109, 109/108, 108/106, 109/109, 108/107, 107/107, 108/110

Please keep in mind, when replacing output tubes on tube amplifiers the tube bias settings must be re-calibrated. So make sure to check your owners manual or contact the amplifier's manufacturer for instructions to make sure you have the skills to re-bias your tube amp.
These tubes are from the estate of an long time audio research employee. Audiogon does not have a (new old stock) condition rating so they are listed as mint.

I will ship the tubes via Fed-ex ground fully insured. The tubes will come in generic white tube boxes. Continental USA sales only.
If you have any questions about the tubes please email me before buying them.