NuTone C905 16 Volt 10VA Door Chime Transformer (1 Pack) Nullify Imported 16-volt, 10VA transformer for use with most NuTone door chimes; order in standard package of six to help assist with your planning and still retain that economical edge Quick install transformers, built to last so you should have fewer call backs One 16-volt, 10VA transformer needed for a single chime cULus Listed for safety, ensuring you have a quality, reliable transformer that will pass inspection