The Rotring centro universal set is engineered for creating precise designs and ease of use. With a set of eight pieces, this compact compass is universally applicable due to interchangeable inserts which include the compass attachment and extension bar. Create circles up to 540 mm. The radius adjusts easily and stays where you want it to due to the static friction in the compass head. From work and school projects to home improvement tasks, the Rotring centro universal set ensures accuracy every time. Comes with lead box for easy organization.