Easy to Use Slide the switch to "On" or "Off" to start and record. Pull the power button to the "ON" position. The purple light will flash twice to indicate the battery level. After the red light (normal recording) or the blue light (voice control mode) flashes three more times, the machine enters recording mode. It has a sensitive microphone.Voice Control Recording Setting Function The document in the machine is set to voice control mode, the voice control number is set to 0, and there is no voice control recording. If there is no sound outside, the recording will pause. If there is noise outside, the recording will restart. The larger the number, the lower the detection decibel and the more sensitive the voice control effect. Large 64GB Capacity, Long Battery LifeThe recorder is equipped with a large 64GB capacity, which can store up to 576 hours of recording files. It can record continuously for 10 hours and has a long battery life. The built-in high-quality 200mAh battery can be fully charged in 2 hours via the USB-TPC interface.Recording and File Management While ChargingThe BJK48 recorder can start recording when powered on. To play back recording files, you can listen to the recording via your computer. Recording Files: Simply connect the recorder to your computer to manage all your recordings, synchronize the date and time, and much more.Small but PowerfulThe voice recorder offers clear, high-quality recordings. This small professional voice recorder can be taken anywhere, you can put it in your wallet, pocket or keychain. The black body and delicate texture make it an ideal gift for students, family and friends.