... OEM 1) 2 rings, 3 rings, 4 rings...2) Ring shape: R(O), D, Q, A; 3) With or ... numbers of rings. For example, 2 ring binders, 3 ring binders, 4 ring binder…etc. More than 10 years in stationery ... traditional products: --Improve the flexibility of the clip, increase strength of the surface shell and make the ... clip more durable; --The grooves increase the buffer ...