This is an APC Smart-UPS SRT extended battery module compatible with the 8kVA and 10kVA SRT-series UPS units, sold to extend backup runtime beyond what the UPS's own internal battery provides. SRT-series units are APC's higher-end double-conversion UPS line typically used to protect racks of servers or critical infrastructure, and an extended battery pack is added when a site needs longer bridging time during an outage than the base unit alone can deliver — common in South African installations aiming to ride out longer load-shedding stages. This is a battery expansion accessory, not a standalone UPS, and needs to be paired with a compatible SRT 8kVA or 10kVA unit already in place.