This is a 4-pad wireless digital launch controller – Reads good/bad continuity of each of its pads, reads voltage from the battery at its pad. Must be connected to a PBU-4 pad-box with its own WRU-c unit or connected wirelessly with a PBU-4w. May also be connected to 4x PBU-1w units. This unit is built into a 6x6x4 NEMA enclosure.