The Elgin 186 watch movement features a bimetallic screw balance and a base plate that has been shortened compared to the Felsa 55 movement. The base plate of the Elgin 186 movement is equipped with four diagonally placed rests. Certain registers mention the use of similar parts for both the Elgin 186 and Felsa 55 movements, hence the data for the Felsa 55 movement is mentioned in brackets. The Elgin 186 movement is a manually-wound movement that was commonly used in the period around 1930.