These positioning squares are suitable for wood/metal right angle, 90 degree welding, very easy to use, just place a square in the corner of the two pieces of material you need to square and secure with a set of clamps. Features: Name: 90 Degree Positioning Squares 11.9 x 12.9 . Material: Aluminum alloy. Shape: L. Dimensions: Length: 120mm, Width: 120mm, Thickness: 16mm. Features: 1. Suitable for crates, shelves, door making, also for outside corners, wood, metal right angle, 90 degree welding. 2. Aluminum alloy, product size: 12 x 12 x 1.6 . 3. Anodized red surface, durable and corrosion resistant, rust prevention. 4. L-shaped, comfortable to hold. 5. Easy to use, beveled edges, easy to handle and will not damage fragile cutting edges. Package Content: 4 x Right Angle Positioning Rulers