Two

Module was built by combining two Synthrotek Euro PCB into 1 MU module. Runs on +-15v. Voltage regulation is in circuit.

http://www.synthrotek.com/products/modular-circuits/echo/

• ? mA +15V
• ? mA -15V
• ? mA 5V
• 2 mm Depth

Available as an assembled Module and as a DIY project.

No info about availability.