This is a Koch Studiotone Combo ST20-C. I purchased this used from Ishibashi Music in September 2024. With a retail price of ¥236,500 (including tax) when sold through the distributor, this is a very user-friendly tube guitar amplifier. In addition to the sound of each of the 3 channels, the recording out sound, which is well-regarded in the Koch LB120II, is also excellent. In addition to the main unit, a footswitch, power cable, instruction manual, and expired warranty card are included. Regarding this item, there was a popping noise when switching channels with the footswitch from the time of purchase. I requested repairs through Ishibashi Music to Okada International, but they said it was impossible to completely eliminate the noise. I have not used this for live performances, and I have been switching channels using the front panel controls, so there were no practical problems. Therefore, I think it's best for those who want to use this amp live, switching channels with the footswitch, to refrain from bidding due to the aforementioned problem. To reiterate, there are no problems with operation from the front panel. I have tried to describe all the points I noticed, but there may be some points I missed. I am an individual user and believe there are no problems with normal use, but I cannot perform electrical inspections. Also, as mentioned above, I cannot guarantee the current condition of the vacuum tubes or other components, so please assume that you will have to have it maintained by Okada International at your own expense if anything arises. Please bid only if you agree to no claims, no returns, payment within 24 hours of winning the bid, and confirmation within 24 hours of receipt. Please refrain from bidding if you are overly concerned about details.