GBC Premium Matte CombBind Binding Spines, 0.375-Inch Spine Diameter, Black, 55 Sheet Capacity, 100 Spines (4090308) Textured finish blends in with your cover. Updates the look of a comb bound document. Available in frost and black, in a variety of sizes. For external client meetings. 3/8 Inch spine diameter with 55 sheet capacity