... 2 rings 2) Ring shape: R(O), D, Q, A; 3) With /without booster; 4) 12 years in manufacturing; 5) OEM 1) 2 ... rings, 3 rings, 4 rings...2) Ring shape: R(O), D, Q, ... in manufacturing;5) Pantented product.Loose-leaf ring metal ring binder is usually used in folder production. ... numbers of rings. For example, 2 ring binders, 3 ring binders, 4 ring binder…etc. More than 10 ...