All of drawing compass are put in a robust plastic case. 【High-Quality Precision Tool】The compass and protractor set for drafting are made of zinc alloy steel for reliable performance, which won't bend or flex while in use. The math compass and protractor set are made of PS material, lightweight and clear. Reusable break-resistant carrying case is designed for secure, tidy storage and convenient transport. 【Versatile Applications】The math geometry kit set is a fantastic assistant for those working in machine design, and the geometry compass set is suitable for architects, engineers, draftsmen, builders, roofers, teachers, and students. Perfect for DIY handymen and artists for a variety of geometry tasks. 【Extension Beam Design】The math tool kit equips an extension beam that attaches to the big compass for drawing large circles so that you can draw a larger circle without lots of measuring and connective dots. 【Practical Gifts】The mechanical drawing tools are designed by experienced math experts with all essential items for teachers and students at any level. A good choice for teachers and students. It's also a perfect gift for your kids and friends, easy to take to class and store in the classroom and at home. Just choose it as school season gift or Christmas gift.