The ETA 7750 is a relatively thick chronograph movement. A legendary movement, robust and reliable but quite thick, standing at 7.9mm thick. The ETA 2894 on the other hand measures no more than 6.1mm. People are saying that the ETA 2894 is not a true chronograph movement, it only has a chrono module mounted on top. Whereas the 7750 on the other hand is a true chronograph. Can someone help me to understand this because I don't really understand what the meaning of true chronograph means (I know what a true GMT means, wondering if its something similar?). I'm thinking of building my own watch one day with an ETA movement and with the thinner 2894 movement, it's more appealing to me. If I were to go for the ETA 7750, I would choose the ETA 7753 variant because I like the 3/6/9 dial layout.