Features: Wireless Explainer - Transmitter, mainly through the equipment to pass the voiced content, and the receiver in the same - channel can be realised by one person to explain, more people to listen. The use of 2.4Ghz frequency , with interferences resistant ability, high confidentiality, multiple channel. Channel number, signal and other basic information are displayed through the LED screen. With keys and knobs to make the product easy to operate, beautiful and generous. Support key pairing, saves time of pairing multiple transmitters one by one. Long transmission distance, 100~150 metres without obstacles. Specifications: Support: LED display Product Model: Transmitter Operating temperature: 55℃~125 Talking distance: 100~150m barrierfree distance Number of channel: 36 Frequency: 2.4GHz Battery capacity: 1200mAh Base usage time: about 11hours Charging interfaces: DC5V1A (Type-C) Product colour: As Pictures Component: ABS+Display Package tupe: Receiver/Transmitter/ 1Transmitter+3Receivers Package Includes: 1Set Wireless Transmitter/Revceiver note: Due to the problemsof lighting effect, there mightbe certain tolerances in product, please understand. Please allow 0-1cm error due to the measurment.