The K&K Sound Big Shot Internal is a single-head piezo pickup, especially designed for bigger instruments with low mechanical resonance. The extra strong output signal makes it a versatile choice for a variety of instruments. These include instruments made of relatively thick material, such as the sound board of a piano. It is considerably harder to induce vibration on these thicker materials compared to the thin top of a violin, for example. As the piezo crystals react to corpus vibrations, a low surface vibration results in a low signal and a strong vibration creates a strong signal. The frequency range is nearly linear with a slight peak in the upper midrange. This allows for great upfront sound transmission. The Big Shot Internal includes a prewired internal endpin jack. The internal jack can be mounted from the outside so no soldering is necessary. The pickup head is attached with a special double-side adhesive film (included), which is UV resistant to ensure safe adhesion even after years of use. It is ultra-thin and enables the harmonic frequencies to completely pass through to the pickup disk. Technical Specs Pickup head diameter: 3/4" Height: 1/32" Impedance: High ohmic Length of connection cable: 1 ft. Jack: Shielded Endpin Jack (stereo TRSS type, connected mono), internal mount, no soldering necessary