The Shure Beta 91 is specifically designed for kick drums and other bass instruments. It combines superior "attack" and "punch" for studio quality sound, even at the extremely high sound pressure levels encountered inside a kick drum. Its boundary effect design produces a strong, solid low-end response that has been specifically tailored for heavy bass applications. The microphone's cardioid pattern provides outstanding gain before feedback and excellent rejection of unwanted sound, making the Beta 91 ideal for live concert applications. No external mounting hardware needed, just throw it in your kick drum and play! Produced with Shure's legendary quality, ruggedness, and reliability! Specifications: Signal-to-Noise Ratio - 59 dB re 94 dB SPL Output Impedance - 150 ohms (actual) Polarity - Positive pressure on diaphragm produces positive voltage on pin 2 with respect to pin 3 Cable - 4.6 m (15 ft) heavy-duty, two-conductor shielded, TA4F to TA3F connectors Case - Matte-black, painted, die-cast, zinc-alloy case with matte-black steel grille Dimensions - 3.75 in. x 5.08 in. x 0.75 in. Net Weight - 13.5 oz less cable