Our standard plastic binding combs, mainly used for binding A4 size (210mm x297mm) paper/document consisted of 21 plastic rings. These are used in office documents, business proposals, presentations, reports, menus, family papers and other matters. They are made of very quality plastic, very durable and can be re-used. The binders can be open and close repeatedly without damage to it, allowing for pages of paper to be added or removed accordingly. They come in various colours and different diameter sizes for all variation of number of pages to be bound by it.