Pocket watch movement without dial, hands, motion work or case. It has a full-plate fusee movement, signed and numbered, with a lever escapement and plain balance with regulator. The watch incorporates Hutton's patent 'resiliant stud' in which the outer attachment of the balance spring is attached to a flexible straight spring enabling the side pressures of the balance spring's expansion and contraction to be lessened. This was thought to increase the watch's isochronism (period being independent of amplitude). The device was patented in 1846.