1. There are many small protruding particles on the outer wall of the water cup. The shapes of convex particles are different, some are spherical at the top and some are prismatic.

2, because there are many nerve points on the hand. When drinking water, rubbing and rotating the cup by hand can stimulate some acupuncture points on the palm of your hand, eliminate hand fatigue caused by long-term writing, and achieve the effect of massage and health care.