Big sizes for big concepts — the compass’ legs measure 17″ long. it holds markers and chalk easily. use this math tool on whiteboards or chalkboards to ensure a whole class can see! Precise drawing tools — compasses are perfect art supplies for making exact curves and circles. this handy drawing tool is ideal for art projects. Durable and steady — made from tough plastic, this teaching tool is designed to withstand many drops and years of use. the hinge and foot feature rubber components to prevent the legs from slipping. Attachments for every surface — the compass features a changeable metal spike, rubber spike and suction cup for stability on multiple surfaces. Fits large markers and chalk — the teaching compass also comes with an attachment, through which larger diameter writing tools can be secured.