MONKA HG9070W ECHO RS Wireless Headset Bluetooth Version: 5.2 Chip: RTL8753 8763 Frequency: 2.4GHz-2.4835GHz Working Range: 10M Driver: Ф40mm Sensitivity: 116dB3dB 1KHZ Impedance: 16Ω15% Frequency Response: 20Hz-20KHz Size: ø6*2.7mm Impedance: 2.2KΩ Directivity: Omnidirectional Sensitivity: -38dB3dB Microphone Frequency Response: 100HZ~10KHZ