Just "snap" the bracelet across your wrist, and it wraps around your arm in place. And you can remove it easily. It's high quality silicone, durable and long-lasting. Safe and Gentle for skin touch, which is proved to be body-safe after rigorous contact test. Measures in inches as well as centimeters (12" / 30cm long), and useful as a straight edge. 11 13/16'' L X 1 3/16'' W