Durable Aluminum Material: This Multi - angle measuring roller is made from high quality aluminum alloy that won't break from mud or rust - more durable and stronger than plastic. Improved Corner Rulers: This set includes six rings with metal knobs at each corner with stylish positioning holes where you can adjust six metal knobs to create your desired shape and find an upward position. Good hole. With its 6 flip-up edges, the user can easily create and measure angles or special shapes from the Angle Finder Tool for increased productivity. Metric and imperial units: these units of measurement are expressed in inches or centimeters. With the laser etched markers, you can clearly read the measurements for years to come. They do not break, discolor or be damaged. Large-scale applications: this versatile tool is designed to create balls, arches, cutouts and anything else you can use for woodworking, brick, wood, glass, stone, laminates, projects construction, works, etc. Use it to mark tiles, floors, bricks, wood, laminate, metal and more