I accidentally (purposefully) broke (sabotaged) the clock hands so I made a pair of new ones with valentine's day theme. The clock hands needs to be thin and well balanced so they don't interfere with each other and not overload the motor. Man, this took soo much time to get right but eventually they look great! Unfortunately, i don't know if this works on other clocks, but I assume they are pretty much the same. The center hole for the hour hand is about 5mm in diameter.