TUNA FUZZ is an effect housed inside a real tuna can! In the early days of its existence as a brand, BEETRONICS produced several effects using actual tuna cans, and this TUNA FUZZ is a tribute to that era. The only control is the Stinger knob, which controls the master volume. However, the sound is extremely well-balanced and tuned, and it's a superb finish from BEETRONICS that connects all kinds of vintage fuzz tones. It uses the same three-transistor configuration as the Octahive, but it has a very dynamic, rich response and considerable volume. It's also great at controlling gain with guitar volume and nuance. Don't be fooled by its silly tuna-can appearance; this sound is serious. TUNA FUZZ is made from real tuna cans, individually drilled and crafted with the utmost love in the BEETRONICS workshop (don't worry, it doesn't contain any real fish!) The super cool Tunabee designed PCB is visible through the clear plastic back cover. Furthermore, the Japan Limited Tairyo model features a special design inspired by the Tairyo flag (large fishing flag). The traditional Japanese design, interpreted in the BEETRONICS style, and the bold Japanese character "Tairyo" (large fishing flag) create a powerful impact that rivals the sound. For a super cool play, step on a can of tuna that says "Big Catch." What could be cooler? 9VDC center negative. Batteries cannot be used. True Bypass Due to the nature of the product, some packaging may have cracks or dents. Please note that this is a normal part of the product's specifications.The power supply is DC input only. Damage to the housing caused by turning the unit on or off while putting weight on it is not covered by the warranty. Thank you for your understanding.