Genuine American-made Western Electric surface-mount ringer ("mechanical bell"). Sounds like a "classic" telephone -- not a chirp or a warble.
Install where you need ringing but not a phone, or to ring on line-two for a two line phone that has just one bell.
Has two modular jacks, or use screw terminals. Volume adjustment lever. Rugged metal chassis with plastic cover. Price includes shipping to any destination in the USA. One-year warranty. Limited stock -- don't wait if you need one.