This relay module contains two 5-volt SPDT 10-amp relays, optoisolators, status LEDs, clamping diodes, and transistors to drive the coils. A single-row 0.1-inch-pitch male header provides connections for logic inputs and relay coil voltage. Connect the load via the onboard screw terminals. The logic inputs are optically isolated from the coil, with separate grounds for coil and logic. A removable jumper (included installed) optionally connects logic ground with coil ground. Four mount holes in the corners of this board allow for sturdy mechanical attachment.