I purchased this on Mercari about a month ago. It was modified when I bought it. It works without any problems. Below is a copy of the description by the maker: Compared to the original, this modification provides a sound with more punch and luster. ★ The toggle switch on the left side of the unit allows you to switch between the normal mode, which features the mid-range characteristics of the TS, and the high-gain & FAT mode (Keeley Baked Mod Mode), which adds thickness to the core sound. ★ The 3-way switch on the right side of the unit allows you to select clipping: TS (Tube Screamer), DB (Dumble ~ Comp Cut Booster Mode), and MS (Marshall Governor TUBE) modes. ★ TS-808 MOD has also been implemented. ■■■TWIN DRIVE mode■■■ By switching the footswitch added on the top of the unit, it switches to the (GAIN②) knob on the side of the unit. Practical use is possible, such as setting different settings for backing and lead and switching instantly. The ON-OFF check lamp is ultra-high brightness BLUE (blue) during normal operation, and the check lamp switches to ultra-high brightness RED (red) in BOOST mode. The OPAMP is equipped with JRC4558D. A socket is installed, so it can be replaced freely. Both 9V batteries and AC adapters are supported. ※ Since this is also listed on other sites, it may end early. Type...Electric Guitar Manufacturer...Ibanez