The Progressive Louver from Wilson Tool can produce louvers of any length and has a universal holder design including a spring loaded adjusting plunger for quick and easy length adjustments without the need for shims. The replaceable inserts will lower your costs and allow you to convert them to different size louvers. When changing material thicknesses, only a new pocket insert is required. Keying at 0°, 90°, 180°, and 270° is standard.