Wing-slot style installation, double-piezo transducer. The Bass Max is an upright bass transducer. It uses a "sandwich" design with two piezos layered together, one facing up and one down. This allows for a quick and simple wedge-mount into a bridge wing and ensures even transmission from the strings and from the body of the instrument. Technical Specs: Diameter: 22 mm, Thickness: 5 mm, Output impedance: high ohmic, Output: 1/4", Connection cable length: 6" • MFSKU Bass Max • UPC 810604020140