2pc Philips 2.4GHz Wireless Microphone Sound Recorder/Collector - Black Philips DLM3538C Wireless Microphone for Steady Long Range Sound Reception in All Directions The 2.4 GHz frequency band allows you to receive sound up to 164.0 ft (50 m). Omnidirectional so you can pick up sound from all directions without affecting the orientation or angle of the microphone. The audio input by microphone is converted to digital signal by DSP to reduce ambient noise and noise elements to transmit clearer voice. When power on, the transmitter and receiver will automatically pair together. The transmitter and receiver can adjust the volume level of 0-4 to achieve a more accurate recording effect Product Specifications: Battery Capacity: 3.7 V / 250 mAh Input: DC 5V/200mA Charging Time: Approx. 2 hours. Usage Time: Approx. 8 hours. Transmission distance: Approx. 164.0 ft (50 m) (without shielding) [External dimensions] Transmitter/Receiver 1.8 x 1.7 x 0.8 inches (46.3 x 42.1 x 20.4 mm) Weight: Transmitter approx. 0.8 oz (23 g); Receiver approx. 0.9 oz (24 g). Special Feature： Clip Battery Indicator Light, Battery indicator light Low delay Mute Function DSP Noise Cancelling Automatic pairing Mute function Monitoring Includes 1 x Transmitter 1 x Receiver 1 x USB-A & Type-C Charging Cable 1 x USB-A & Type-C Audio Cable 1 x Type-C & Type-C Audio Cable (for Smartphone) 1 x 3.5mm 3 Pole Audio Cable for Camera 1 x Storage Case 1 x User Manual