Designed with takram design engineering
A piece of string whose both ends are just ringed is able to use as bookmark for any size of book. The rings will stay in order and not come lose like edge of string. It is also used to hook through your finger when you open a book.
両端をリング状にしただけで、どのサイズにも使用できる後付けの栞紐。栞の先端がほどけてくることがなく、本を開く時にリング状の栞に指をかけることもできる。