Shuokecrafts 2pcs Letter Size 3 Ring Binder Mechanism,3 D-Rings, 2.5 Inch Capacity, 11 inch Sheet Size, 36mm Base, No Boosters 1.These nickel 3 ring binder mechanisms are designed to hold standard sized 8.5” x 11” sheets. 2.The time tested and durable design ensures years of use at home, school, and in the office. 3.These are great for those who want to create their own custom binder. 4.No BoosterS, 11" oveall length, 3 D rings,inner diameter 65mm(2.55"),36mm base width.