This is a custom-built Maxon (Ibanez) SD-9 Sonic Distortion, based on a circuit board purchased from the overseas site "aion fx." It's housed in a smaller enclosure than the original, resulting in a tight fit. The lid has been slightly modified to close, and may require a bit of finesse when opening and closing. The original op-amp was a JRC4558D, but this unit features a Malaysian RC4558P chip. The op-amp is socketed for easy replacement. A JRC4558DD is included as a bonus, allowing you to swap it out and compare the sound. I haven't owned an original SD-9, so I can't comment on the sound difference, but theoretically, it should sound the same with a JRC4558. Please note the correct orientation when installing the op-amp. True bypass. I built this for my own satisfaction, and have only tested the sound. Sound has been confirmed with both an adapter and a 9V battery. ・Knobs: Left: Volume Middle: Tone Right: Distortion The toggle switches control the distortion character (left) and the tone's effect (right). I've included photos of the website's English description. The bottom settings on both switches are the original SD-9 specifications, while the others are MODs. I found the MOD tone settings to be more user-friendly than the original. Returns are accepted if there is a critical malfunction upon arrival. 9V batteries and adapters are not included; please provide your own.