The AB0204 board has 4 microphones spaced 25mm apart in a linear arrangement.
The board includes the A2B transceiver to provide a small form factor array for audio product prototyping. The AB0105 module provides 4 microphones in a Y arrangement.
Complete details - datasheet, user guide, and drawings - are available from the Clockworks website.
The AB0204 is available in single and discounted 5 packs.