Liebert's PowerSure PSP, 500V Single Phase UPS is an off-line UPS design with a Stepwave output. The Powersure PSP includes alarm silence, continuous overload detection, hot swappable user replaceable batteries, four battery-backup and two surge only outlets, and lightning and surge protection. Output Receptacles: (4) NEMA 5-15R (orange), Battery backup and surge protector, (2) NEMA 5-15R (black) Surge protection. Voltage (Battery Mode): 120VAC plus or minus 8 percent.