Two-Hour Backup Power with FGD-W610-B FGD-W610-B Sensaphone Battery Backup is a module for 2 hours backup power for the Sensaphone Web600 not included . Rechargeable battery and charge control circuitry keeps battery fully charged while connected to a powered WEB600. When the main power source fails, the FGD-W610-B provides uninterrupted power to Sensaphone WEB600 . This unit will not work with the original Sensaphone Web600 that has a four prong input. Web600 must have a two prong output to work with the FGD-W610-B. Contact the manufacturer for availability of the four prong units. With a short cable included with the battery module, FGD-W610-B Battery Backup. Connects to the WEB600. The unit charges the battery and monitors its charge level when once it is connected. The charge status can be monitored on the summary screen. Note that upon initial connection it takes about 5 minutes before the WEB600 recognizes the connection of the FGD-WG10-B Battery Backup. Once the sensor seesthe battery, the battery channel will be enabled on the Battery programming screen.Warranty 12 months by Sensaphone This item ships from a separate warehouse and may require extra time for delivery.