SPECIALTY PUMPS 12 Volt Battery Back-up Sump Pump System Model RBSP, Part No. 24963B500 Designed to back-up residential sump pumps during a power outage or primary pump failure Water level sensor and built-in alarm assure automatic system start-up to protect basements against water damage Continuous, self-charging system operates from a 12 volt battery (not included) Pumps up to 20 GPM