The movement in the 390 rep is the Asian 6497 high beat clone. It's a manual wind with about 40h powere reserve. You have to wind it fully to get the full reserve. You will know it's fully wound when it becomes tough to wind and then you won't be able to wind it any more. There is no automatic rotor, so you must re wind the mainspring before the power reserve is up, or the watch will stop. Letting the movement stop won't hurt the watch, but then you will have to set the time again. Good luck with it and post some pics.