The NOTIFIER NF50 Series Single Loop intelligent fire alarm panel, has been developed for both installers and end users with efficiency in mind, offering a technically advanced range of facilities and functions while remaining easy to install, program and operate. Three models are available in the NF50 series. The compact NF50-A1 , the NF50-B1 with internal printer option and a larger separate power supply and the NF50-C2 with internal printer option, a larger separate power supply and added space for 72 hours battery back-up.