What we like about this digital audio recorder: Aside from the fact it's a professional-grade device with a price not much greater than consumer grade, it has an extra long battery life. This solves the number one weakness of these kinds of devices. K-MIC-OTG Voice Activated Digital Audio Recorder 688 Hours of Recording Long Battery Life Power Bank - Play Back on Recorder, Computers, Phones, Tablets. Professional Grade Digital Audio Recorder with Extra Long Battery Life Customizable Settings The K-MIC-OTG professional voice activated audio recorder was designed to fit almost any circumstance. It includes headphones so you can listen to audio recordings anywhere. It also functions as an MP3 player and power brick. You can also listen to recordings on phones, tablets, or computers. It includes an OTG adapter for phones and tablets. Plug it into your device and listen to your recordings. Features: 250 day standby battery life. Stores up to 688 hours of recordings. Functional 5000 mAh power bank to power your phone or other devices. Functional MP3 player - plays audio recordings or MP3s you load to the recorder. High quality microphone picks up conversations from as far as 40 feet away, voice activated or continuous recording modes. Time and date stamp. Hidden magnet for cover deployments. Listen to recordings using the included headphones or connect to almost any computer, phone, or tablet. Control microphone gain, voice activation noise level trigger, file size and bitrate, recording file format (MP3 or WAV), and more. Schedule daily recordings - set the time, length, and number of days to automatically record. Customized settings - includes a settings app for windows or manually change settings using Mac or Linux.