Tested and working. Box included. Authorized dealer product. Velcro on the bottom. The Fender Blackface and Tube Screamer, essential to the sound of Stevie Ray Vaughan. This 2-in-1 preamp/overdrive pedal boldly incorporates this combination. It's truly an "SRV in a BOX" pedal. The clipping toggle switch allows you to select between symmetrical (original) or asymmetrical clipping. Asymmetrical clipping enhances the touch-sensitive drive characteristics. The gain toggle switch increases gain and alters the low-frequency response. The all-analog circuit, which follows the path of a Blackface tube amplifier, provides authentic amp tone and feel. It delivers genuine amp sound. It features a full EQ section characterized by a glassy, slightly mid-scooped clean sound. The headroom switch allows you to select between high-headroom solid-state rectified 4x6L6 power amp, or low headroom and sag with tube rectification and a low-wattage 2x6L6 power section. The passive effects loop allows you to connect your favorite pedals between the overdrive and the amp-in-a-box to build your ideal rig. OVERDRIVE Section Gain Tone Volume Clipping SW: Selectable between symmetrical and asymmetrical clipping. Gain SW: MORE provides even higher gain. Headroom SW: 18V mode provides even higher headroom. AMP Section Gain Volume Treble Mid Bass Headroom SW: Headroom can be switched. Bright SW: Provides crisp high frequencies. stevie ray vaughan john mayer TS