Hint: Notice the direction of what you're seeing. For instance here, on MM and date, Both have similar effect on them to the north. 1) can't be RPM or
DDO because MM's are added by hand not hubbed in til later 2)DDO/RPM the size od device is larger OUTWARDS...MD REDUCES it INWARDS 3) Movement at strike is/can be in any and multiple directions, most hub doubling is a turning motion(circular), a twisting or rotation that increases the size.(why some devices are affected and not others or all around the outside but not in the center.