RB12 provides a convenient interface for the U3/UE9 to industry standard digital I/O modules, allowing electricians, engineers, and other qualified individuals, to interface a LabJack with high voltages/currents. The RB12 relay board connects to the DB15 connector on the LabJack U3 or UE9, using the 12 EIO/CIO lines to control up to 12 I/O modules. Output or input types of digital I/O modules can be used. Modules are available (not included) with voltage ratings up to 200 VDC or 280 VAC, and current ratings up to 3.5 amps. The RB12 is designed to accept G4 series digital I/O modules from Opto22, and compatible modules from other manufacturers such as the G5 series from Grayhill. No modules are included. Opto22 modules are available from opto22.com, alliedelec.com, and newark.com. Grayhill modules are available from digikey.com. The RB12 does not require a cable or power supply, and does not ship with a cable or power supply. Not compatible with the U12.