The RPS4000 is a 1U unit with four (4) empty slots which can be populated with (4) APS1000W Power Modules (sold separately). The APS1000W requirement depends on RPS, EPS or PoE application. The rear panel features four (4) embedded RPS connectors, switch selectors for RPS/EPS power modes and switch selectors for power modules two-by-two bridging.