Reliable Material: Made of aluminum alloy, durable and will not corrode. The durable metal woodworking compass will not bend or break during use. Outstanding Design: The precision geometric compass has a tiny pen slot and center wheel to prevent accidental movement of the legs. Take out the fixed pen and fix it perpendicular to the middle coil on the wooden board for easy use. Adjustable Distance: Our extended geometric compass is adjustable from 20mm to 280mm to best meet your woodworking marking requirements. Easy To Use: Just open the compass, unscrew the screw, position the pivot point in the center of your arc or circle, and then fix your pen tip, which is similar to the use of a normal compass. Widely Application: Suitable for engineering decoration design, wood processing, schools, offices, homes, etc. A professional circle drawing tool suitable for students, artists, mathematicians and woodworkers.