The APC Easy UPS 3S Pro is a 3-phase-in/3-phase-out (3:3) UPS rated at 40kVA, 400V, aimed at commercial and light-industrial installations needing serious three-phase backup power rather than single-phase. This unit is configured with 4 internal 7Ah modular battery strings, letting individual battery modules be swapped without needing to power down the whole UPS, and carries a 1-year warranty. The "Easy UPS 3S" range sits as APC's more compact/cost-effective three-phase online UPS line, typically deployed for server rooms, light industrial control systems or small data centres needing higher power capacity than a single-phase unit can provide.