VEMURAM JAN RAY overdriveIt's a firm natural overdrive with a pleasant silky sustain without any unnatural compression. It keeps the characteristics of the tones that the guitars naturally produce to reproduce that great sustaining punchy clear tones of the blackface Fender amps from the 60's. The tone is crispy yet the low is warm and mellow. Works with a standard 9V power supply (not included) or battery.