The Zoom H6 Handy Recorder is a 4-track digital recorder that functions as a mini-mixer with stereo mics as well as 4 XLR mic inputs. It uses SD card flash storage and has a USB port to connect to a computer, where it can function as a digital audio interface. It can record in high-quality WAV or compressed MP3 format.
B&H Photo has a fairly detailed review:
Zoom H6 Handy Recorder available at B&H Photo Video