Easy-to-install lock mount or wall mount that can reduce installation time by 25%|Thermal cut-off switch designed to shut off the door chime system in the event of excessive temperature, NuTone saves you time and money!|Quick install transformers, built to last so you should have fewer call backs|One 8 or 16 V, 20 VA transformer needed for a single chime, multiple transformers needed for two chimes|Ensuring you have a quality, reliable transformer that will pass inspection