APC SMART-UPS RM 1U, 1 kVA, 640 W, 47/63 Hz, 480 J, NEMA 5–15P, NEMA 5–15R, 5.4 min APC SMART-UPS RM 1U. Output power capacity: 1 kVA, Output power: 640 W, Input frequency: 47/63 Hz. AC outlet types: NEMA 5–15P, NEMA 5–15R. Typical backup time at full load: 5.4 min, Typical backup time at half load: 14.5 min, Replacement battery cartridge: (1) RBC34. Form factor: Rackmount, Product color: Black, Rack capacity: 1U. Bundled software: PowerChute Smart-UPS Bundle https://www.alphr.com/apc/apc-smart-ups-1000va/30312/apc-smart-ups-1000va-review This 1,000VA floor-standing UPS tips the scales at nearly 19kg; twice the weight of many of the other products here. Along with this reassuring weight, its battery has good longevity and can supply enough juice to keep a draw of 335W going for 20 minutes.... Not the cheapest, but the management software and range of features make it a winner...