what movement uses "MM" hallmark?

[horologist]

The other day,a collegue came back from holidays and showed me a submariner replica he had purchased in Sydney Australia. He had asked me to open it as he knows that I have the bergeon tool for opening the back. I noticed that the movement had been modified to resemble the real one especially with the coloured wheels and the rotor pattern but had a slightly slower beat. I looked for the eta symbol but instead found the letters "M M" stamped without any number. Has anyone ever seen a similar replica. I was surprised that even the rehaut just under the crystal was engraved with a serial number which is not found with the higher grade relicas I have recently purchased???. I am sorry that I do not have pictures to show you as it isn't my watch.

[rollie master]

asian 21 jewels