A twin-bell clock is a mechanical clock with two bells rung by means of either a mainspring or, in electrical models, an electromagnet and armature. These clocks typically have an old-fashioned, antique look to them.
The first American mechanical alarm clock was a single-bell model, invented by Levi Hutchins in 1786. The classical form of the twin-bell clock has a round face, two bells on top, a handle and two short legs for standing upright on flat surfaces, such as nightstands. The retro twin-bell style continues to be popular, and many large manufacturers across the world produce a variety of designs.