Great looking slide buckles. Their curved shape, large mouth opening, and recessed center bar make them the perfect choice for thicker straps. These are for 1″ straps, the opening is 1″ wide. The large mouth opening is a generous ⅝” on either side of the center bar. The metal itself is 5 mm wide at the short ends, 4 mm wide at the long sides and 3.5 mm thick. Overall (outside) measurement is 1-¾” X 1-¼”.