Unibind (10pcs) 7mm 40-55 sheet capacity BLACK STEELBOOK Letter Size 8.5" by 11" (Case Bound on 11" edge) Center Cut (3.75") window placement Top Cut (2.5") window placement. PLEASE SPECIFY 45-55 sheet binding capacity 8.5" x 11" (case bound on 11" edge) Unibind Steelbook (Hard covers)