The APC RBC57 replacement battery cartridge #57 is a high-performance, safe, eco-friendly replacement battery cartridge for uninterruptible power supply (UPS). This sealed lead-acid battery comes with suspended electrolyte to ensure leak-proof performance, and delivers a long-lasting battery life. It includes all required connectors and is hot-swappable, making installation a breeze. It’s also maintenance free, saving you much hassle. The environment-friendly design helps protect the environment.