BUYERS PRODUCTS, 3/4 in Ring Dia., 26,500 lb Capacity GVW, D-Ring - 30PD40|B46 - Grainger
Duo D-Ring 16 mm – Plastic white, size 120 mm (4 3/4″) | Herm. Sprenger USA
Amazon.com : BinderRings Magnetic D-Ring Binder Mechanism (10 Pack), 3-Ring Binder 1-inch D-Shaped Rings for Standard Letter Paper (8.5 Inches x 11 Inches), Includes 10 Vinyl Sheet Protectors : Office Products