The Radial ProDI is a high-quality, passive mono direct box that's perfect for use with acoustic guitars, bass guitars, electric pianos, and synthesizers. The ProDI's custom transformer helps to deliver the highest performance possible, virtually eliminating issues with noise. And, as with all Radial DI boxes, the ProDI is incredibly reliable and easy to use — just plug in your mono instrument and instantly eliminate ground loops, while enjoying a rich, full sound. If you need the same excellent quality in a stereo version, Radial also offers the ProD2 stereo version. Raidal ProDI Passive Mono Direct Box at a Glance: Full-range passive direct box Custom isolation transformer eliminates noise Really easy to use Built like a tank Passive vs. Active DI The Radial ProDI and ProD2 (stereo version) are full-range passive direct boxes. Active direct boxes employ electronic circuits to change the impedance from hi-Z to lo-Z and balance the