Item: microphone, model: sx21, type: condenser, mute function: yes, frequency range: 20hz – 20khz, signal-to-noise ratio: 64dbm, audio sensitivity: -42 db, impedance: ≤ 2.2 kω, maximum spl: 110 db, polar pattern: omnidirectional, power source: built-in rechargeable battery, wire length: wireless (no wire), connectivity: wireless, package includes: 1x microphone, 1x charging cable, 1x user manual, 1x carrying case, other features: enc noise cancellation, magnetic clip, 360° audio capture, compact design, microphone type: digital, input voltage: 5v, battery capacity: microphones: 110mah (x2 = 220mah), charging case: 800mah, battery life: up to 9 hours, transmission delay: 30ms, transmission range: 20–30m (no obstacles), key features: compact & lightweight, mini-sized, round design ensures portability and ease of setup.