The APC Replacement Battery Cartridge #43 fits selected APC Smart-UPS and Back-UPS models, restoring power back-up capacity for home offices, small businesses, and IT departments. This replacement battery cartridge (RBC) has a lifetime of three to five years, offers safe and reliable support to the UPS, and extends the useful life of your UPS. The APC RBC #43 comes fully assembled and includes easy-to-follow replacement instructions, making hot-swap installation simple. APC RBCs are compliant with international regulations and safe for transport. They include instructions and reusable packaging with prepaid postage for safe disposal of old cartridges.