VR-428 This is a month duration precision regulator by Hawelk. Hawelk was one of the preeminent makers of the last half of the 1800's. In addition to being a month runner, this regulator uses a pendulum patented by Satori. The pendulum rod is a piece of solid, fused quartz. There are 12 of these pendulums known in the world. Note the unusual, and wonderfully "industrial" beat scale mounting. This is a very unusual, and very rare piece and has been completely restored and runs perfectly.