Helps achieve perfect 90° circular saw cuts. Built in guides square Pro Cut to the workpiece while two rubber strips prevent side-to-side movement. Instantly aligns saw to the cut line whilst reducing dangerous kick back, binding and bent blades. Ideal for cutting timber, siding, I-beams, trim, stair treads etc. 6” hook rule and 45°/90° layout squares. Fits all 81/4” and smaller right blade circular saws.