Please note: the physical slightly color difference or difference, does not affect the use, please do not mind, thank you! The 90 degree positioning square can be used with the clamp to position the joint angle of wooden boards for gluing or welding at right angles. They can also be used in 90-degre jigs and fixtures. They can be secured to corners with spring clamps or small F-style clamps and work on both inside and outside corners. Sturdy Material: Featuring a high-impact materials construction that insures optimal and usability.They are made from tough unbendable impact for extreme durability and rigidity. They maintain their squareness and not flex even under the load of larger assemblies. 3 Different Sizes: 3 inch 4 inch 6 inch, for more woodworking workpieces. Applicable to any thickness of wood.Can also be used for securing small picture frames where other large sqaures unable to fit it. Wide Application: You'll have what you need to create square boxes, drawers, cabinets, cabinet carcasses,picture frames,face frame, etc. This is also a great gift for woodworkers. Color: Material: plastic Package Contents: 1 x 90 Degree Corner Clamp Clamping Square Set Only the above package content, other products are not included. Note: Light reflection and different displays may cause the color of the item in the picture a little different from the real thing. The measurement allowed error is +/- 1-3cm.