Please note we supply 2 different versions on this item –  Standard motor model & High-quality Japan motor.

Staring voltage: 6 volts.

Operation voltage: 7~10 volts.  [Standard motor]

Operation voltage: 7~12 volts. [High-quality Japna motor]

Please DO NOT use high voltage over than 12 volts, which is unnecessary and may cause trauma to the skin.

Tool-less stroke adjustment: simply turn the gear wheel to change the strokes. The machine features 9 different strokes.

The standard motor model is slightly bigger, but they are of nearly the same weight. (110 grams)

We highly recommend you buy the high-quality motor model which is much better.