MAXTECH 18140MX 4-in-1 Multi Square Highly durable extruded aluminum frame and heavy duty ABS housing Double sided tape lock for right and left handed users Integrated v-groove on bottom of square for measuring piping and conduit Incorporates features of framing square, tri square, mitre square and protractor square Sliding and lockable straight edge makes it easier to guide MultiSquare on workpiece without taking up much room in toolbox