... bird song playback output Cheapest Hunting Equipment Hunting Calls Can Do OEM 1.FeaturePower supply with Li-battery or ... the DC power, built-in lithium battery, lithium battery can be charged2Power SwitchTurn on/off the power supply3SD Card ... light8RF AntennaWhen long-distance remote ,pull it out,it can enhance the emission signal9External Amplifier PortConnect external stereo amplifier10Battery ...