We're finally punching louvers! The Metal Machine louver press makes traditional-style 21/2-inch round-top louvers. The depth is adjustable by turning the nut on the upper head (A). Punching evenly spaced, centered louvers is easy (with some practice) since the rear side of the jaw is scribed with a centering line which can be aligned with a scribe mark on the sheetmetal. The previously punched louver can be squared up against the edge of the lower head (B) to help ensure even spacing.