According to the Omega museum, these pocket watches, used for Olympic timing were never sold to the public and belonged to the Omega Timing department. Each example is numbered on the dial (in this case 3) and features a modified caliber 1130 that allows, via electric contact, the last five seconds before an elapsed minute to be recorded via an opticalacoustical system. For a similar example see Omega a Journey through Time by Marco Richon page 566.