This listing is for one ART Pro Channel I channel strips fitted with 1981 NOS Sylvania 5751 grey plate 2 mica tubes in all three tube positions. Tubes were burned in for 24 hours under load, and are matched and balanced per pair across the preamp, compressor, and EQ tube sockets with the other unit I have for sale. Tubes have maybe 30 total hours on them. These tubes are an order of magnitude better than the stock tubes. They are quieter and sound very warm. You are getting approximately $75 worth of low-hour NOS tubes with each unit. Pots and jacks were recently cleaned. You will receive one of the two units in the pictures with this listing and must buy both to get the pair.