Avery Mini Durable 3 Ring Binder, 1" Round Rings, Holds 5-1/2" x 8-1/2" Paper, Label Holder, 1 Black Binder (27257) - Walmart.com
Amazon.com: Mr. Pen- Loose Leaf Binder Ring, 20 Pack, 2 Inch, Binder Rings, Book Rings, Metal Rings for Index Cards, Rings for Flash Cards, Flash Card Rings, Index Card Rings, Clip Rings,