・Please use a soft ruler at the thinnest part of your wrist, stick it to your wrist in a circle, and measure your hand circumference. You don't need to reserve space for yourself. ・For example, if the measurement is 13.8cm, just remark "13.8cm" in the shopping cart. ・If you don't have a tape measure, you can use a thin wire or earphone wire instead. ・If you are not sure, you can take a photo and send it to us for viewing. If you have a preference for wearing habits, please note to inform: [closer to the skin] about 0.5cm reserved space, will not tighten the wrist [loose] about 1.0cm reserved space, can slide on the arm