Dean, Generally the purpose of "freezing the 12 hour totalizer is due to the movement. The genuine Omega movement is a tricompax ( three working subdials). The movement that is commonly used in a lot of rep Chronographs is the Seagull ST19 which is a very solid movement that is built using the original tooling from the Venus 175, which Seagull bought from Venus back in the 1960's. The Seagull is a Bicompax movement , so it only has two working subdials. Thus the need to "freeze" the non functional subdial. Sent from my iPad using Tapatalk