Control presence :+/-12dB at 8KHz Bass Control: +/-12dB at 600 Hz Middle Control: +/-12dB at 600H Frequency Response: 20Hz - 20KHz Power: 9V alkaline battery Product Description Introduction: Under the saddle pickup for acoustic guitar Pre-wired for easy assembly 4 bands plus volume control Supplied with a battery box, Low battery indicator. Connecting wire with 2.5mm plug included : dimensions: 10.5 (L) x 4.7 (W) x 6 (H) cm (4 x 1.9 x 2.4inches) Treble Control : +/- 12dB at 2.2KHz Materials: plastic + electronic + copper Package Includes: 1 x Pre-Amp plus pickup 1 x Connecting wire with 2.5mm plug 1 x 9 Volt battery 1 x Mounting base with sticker 4 x Mounting screws 1 x recording rod 2 x gasket 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.