This is a 4-pad hardwired digital launch controller – Reads good/bad continuity of each of its pad, reads voltage from the battery at its pad. May be made wireless by plugging in a WFX WRU-c wireless unit. All features work hard-wired or wireless. Must be hardwire connected to a PBU-4 pad-box or connected wirelessly with a pair of WRU-c units. May also be connected to up to 4x PBU-1 units hardwired or wirelessly. This unit is built into a 6x6x4 NEMA enclosure.