Size - The note-taking wristbands measure 238mm x 29mm( L*W ), 2mm thickness. Can be adjusted to fit most people's wrists. The width is sufficient for recording most information. Material: The reusable slap bracelets are made of silicone, which is wear-resistant, soft, comfortable and waterproof, no need to remove it when washing hands or sweating. With writable coating, easily erasable with an ordinary eraser, making them reusable. Features - The waterproof memo wristbands can record to-do lists, shopping lists, etc., help with time and task management in daily life. It can remind oneself at all times by firmly attaching to the wrist with a light tap. The back has clear metric and English scales that can serve as a ruler. Application - The sports memo bands are for various groups including sports enthusiasts, elderly people, forgetful people, engineers, office workers, housewives, etc. They are widely used in offices, outdoors, homes, and other occasions.