Our A4 1/2-inch 4-ring binder mechanisms (16mm capacity) are manufactured to the highest standards of quality and consistency and feature a bright nickel finish that will bring a professional look to your binders. A4 ring mechanisms are designed to accommodate international A4 paper which is 210mm x 297mm (8.27” x 11.69”). The D-style rings are spaced 8cm apart (3.125”) which is the international standard for A4 binders. OUR BINDER MECHANISMS ARE SOLD BY FULL CARTON QUANTITY ONLY.