NuTone C907 16V, 30VA Transformer 16-volt, 30VA transformer for powering multiple door chimes in one home; 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, 30VA transformer powerful enough for up to three chimes saving you installation time cULus Listed for safety, ensuring you have a quality, reliable transformer that will pass inspection