2 layer board of 3.52x2.42 inches (89.31x61.39 mm). Digital Stereo Audio Tranceiver - Based around the Texas Instruments CC8531 PurePath wireless audio SoC, CC2591 Range Extender, and pcb antenna. The front end is a TI stereo PurePath codec chip which handles line level inputs and headphone amplification. Design based off the TI Headphone Module. Intigrated usb charging circuit for li-ion batteries.