Assertion: doorbell's transformer | /r/HasProperty | required
Facets:
Source sentences:
text: Note: If wiring your Ring Doorbell 2 to an existing doorbell, a transformer with a voltage of 8-24 VAC is required.
text: Ring doesn't explicitly state that the transformer is required, though: "This kit contains the transformer we recommend for powering a Ring Video Doorbell Pro along with a 16-24 volt AC doorbell chime (required).