Little Yellow Duck Wireless Bluetooth Singing Speaker Microphone Karaoke Smart Toy Children's Microphone--Built-in battery capacitynull Signal-to-noise ratio≥60dBFrequency response range100HZ-20KHZ Rated power5WLogistics serviceExpress delivery Shell processabsBattery lifenull Radio headCapacitorIs it built-in batteryBuilt-in battery--k3¥39--k5¥29