The Johnson Mach-1 Johnny Square is a professional-grade 7-1/4" rafter square built from solid aluminum with CNC machined edges for precision accuracy to 0.001 in/ft. Features an innovative Smart Mark cutout system and built-in level vial for faster layout work.

• 7-1/4" solid aluminum body with CNC machined edges
• Smart Mark cutouts for stud, joist, and LVL layouts
• Built-in replaceable level vial with 320 degrees of visibility
• 22.5, 30, 45, and 60 degree angle slots
• 1/16" ruler graduations with laser etched Hi-Vis markings
• 1/8" scribe notches for ripping lumber
• V-notches at each roof pitch for common top cuts
• 1" wide heel stays seated on split and irregular materials
• Matte black anodized finish reduces glare and resists corrosion