Features: Dual audio mixed output function. Multi-function remote control Built-in 50W speaker,the volume up to 150dB. Support a external speakers output. With 2 forceps of wire and use 12V power. USB 2.0 Transfer rate. Built-in memory Card A and memory Card B,mixed output. Packing list: Bird caller host *1 Remote control*1 23A 12V Alkaline battery*2(Use for remote control) USB cable*1 user'smanual*1(in English)