Wren & Cuff Germanium Compressor / Preamp, compressor / preamp effects pedal, hand-matched germanium transistors, versatile 4-knob layout for broad tonal range, wide control range from a barely noticeable compression all the way to total old-school dirty squash, great on electric guitars and bass guitars, true hard-wire bypass, controls for Volume, Compression, Release, Attack, bypass footswitch, status LED, metal housing, 6.3 mm mono in / output jacks, power supply via 9V battery or optional 9V DC adapter, 2.1 x 5.5 mm barrel plug, polarity (-) center (battery is not included in the delivery), current draw 11 mA, dimensions (L x W x H) 121 x 65 x 40 mm / 4.7"" x 2.6"" x 1.6"", weight 284 g / 0.62 lbs, made in the USA