High-quality material: Made of aluminum alloy with anodic oxidation treatment, it is durable and rustproof. High hardness, rustproof, non-corrosive, long-lasting use. Perfect 90° corners: This precise clamping square is designed to be clamped on boxes, frames, etc. to facilitate squaring during gluing. This right-angle positioner has two additional notches. True right angle for internal and external squares. Base and fold for straight and parallel. How to use: Place a square at the corner of the two pieces to be squared and secure it with a set of clamps. Metric and inch graduations. Accurate calibration, easy to use, will not easily damage fragile cutting edges. Available in 12 cm and supplied in a pack of two. Professional design: Designed to be clamped on boxes, frames, shelves and for external corners, etc., to facilitate squaring during gluing. Beveled edges, easy to handle and won't damage fragile cutting edges. Wide Application: You'll have exactly what you need to perfectly