Individual flip-folder windows each hold two pages of marching band sized music - one front, one back. Constructed of heavy black paper with a clear plastic cover on both sides. Two holes are punched along the top for use with flip folder sets. Works with Selmer Plasti-Folio music holders and other brands with similar sized windows. Specs: • 5-3/4 inches high • 6-15/16 inches wide • Two holes, 4-3/8 inches apart on center