The E73 Pro Journey AUX BT Audio Receiver Transmitter lets you play music or send audio wirelessly It works in both receiver mode and transmitter mode so you can plug into AUX devices or send audio to Bluetooth headphones It uses Bluetooth version 5 0 with chip JL AC6956 for stable connection and low latency Its compact size 34 by 59 by 13 mm and weight only 23 grams make it easy to carry and hide Powered by a 250 mAh battery it offers about 10 hours working time in receiver RX mode and about 8 hours in transmitter TX mode Standby time reaches up to 200 hours Charging takes about 2 hours via USB One key switching between RX and TX modes plus 3 5 mm plug ensures compatibility with many devices Car stereo home speakers or headphones and more Key Features AUX to Bluetooth or Bluetooth to AUX transceiver device Bluetooth 5 0 chip JL AC6956 for stable connectivity Compact design 34 x 59 x 13 mm lightweight 23 grams Battery 250 mAh with about 10 hours RX working time and 8 hours TX working time Long standby time up to 200 hours Fast charging about 2 hours via USB 3 5 mm AUX plug and one key switch RX and TX modes