You put your fingers through and wear it on your hand. Unlike wrist weights that you just wrap around your wrist, it won't come off or shift even with vigorous movement. The weight is on the back of the hand. The weight is 500 grams (500 grams for the right hand + 500 grams for the left hand). I haven't used it much, so there aren't any particularly noticeable stains that bother me personally, but there might be some slight ones. Therefore, please refrain from purchasing if you are overly concerned about this. It is not fragile, so I plan to ship it in a plastic bag via Takkyubin Compact.