This D250X effect pedal is based on 250 Preamp . 2 functional knobs: Gain and Level controls; Two Models (D/M) to . ON/ OFF LED indicator light. True bypass allows your guitar tone to remain pristine even when the D250X is off. Full metal shell and size, durable and portable. Function knobs: Gain: Controls the amount of distortion, from just a Press of grit to all-out grind. Level: Dials in some body for "always on" performance or huge amounts of boost for boosting solos above a dense stage mix. With the Gain all the way down, crank up the Level to boost your sound and cut through during your solos. Specifications: Input: 1/4 inch monaural Output: 1/4 inch monaural Power : 9VDC, Negative Tips (Regulated recommended) Colour:Orange Material:metal Size:9.2 * 3.8 * 3.6cm Package Contents: 1 * Effect Pedal Only the above package content, other products are not included. Note: Light reflection and different displays may cause the color of the item in the picture a little different from the real thing. The measurement allowed error is +/- 1-3cm.