Materials: ABS Transmitter Weight: 18g Directivity: Omnidirectional Transmitter Battery Capacity: 130mAh Charging Box Battery Capacity: 400mAh Sensitivity: -38dB Signal-to-noise ratio: 65DBM adaptive noise reduction Transmission delay: 25MS Frequency response range: 20-20KHz Charging Time: About 1.5 hours Working Time after Recharging: About 6 hours Transmission Range: 30m Plug and Play One-Click Noise Reduction Magnetic Back Clamp