Unless this winder proves to be unreliable it's a great value. Exceeded my expectations for the price, very quiet and appears to be well made. Easily winds my Rolex Sub and Orient Mako without being overloaded.

I calculated the turns per day (TPD) for the four winder settings that are selectable with the slide switch on the rear of the winder, labelled a-d. Here they are:

Setting a:  430 TPD
Setting b:  982 TPD
Setting c: 1403 TPD
Setting d: 2455 TPD

So far I have only tried setting a, and find that it will sustain an already wound watch, but will not increase the power reserve. This setting keeps my unwound Rolex running continuously but the watch will stop soon after removal from the winder unless it is immediately worn. Setting b will probably actually increase the power reserve on a watch.