This is a BOSS DD-7. It's used, but its operation has been confirmed. The back has been replaced with a plate that allows for Velcro to be attached. The following is from the manufacturer's website: Since its debut in 1986, the DD-3 Digital Delay has been highly regarded by guitarists around the world for its iconic sound and simple operation. The DD-3T is a model that enhances the functionality while retaining the timeless delay sound and intuitive operability of the DD-3. The delay tempo can be set using the unit's switch or an external footswitch, and you can choose from three different note lengths to set. Also, the direct out terminal is laid out on the output terminal side. This makes it easier to connect when outputting direct/effect sounds individually. ■ Enhanced functionality while retaining the DD-3's sound and simple operation ■ Easy operation for instant sound adjustment ■ Delay time from 12.5ms to 800ms, allowing for speedy and detailed settings with three time ranges ■ Tap tempo input is possible via the unit's switch or an external footswitch ■ SHORT LOOP mode allows you to obtain the HOLD effect of the DD-3 and create phrase loops ■ Direct out terminal for individual output of direct sound ■ Output terminal and direct out terminal are laid out on the same side Type: Electric Guitar Manufacturer: BOSS