The compass ruler set automatic lead core window opening model has a metal compass, a 15cm ruler, a protractor, a 45 ° right triangle ruler, a 60 ° right triangle ruler, an eraser and a box of 0.7 lead core. The compass is made of stainless steel metal, which is more durable, with smooth lines and accurate drawing. The maximum diameter can reach 290mm.

The compass has automatic lead core and pen clip. Automatic lead core type, press out core, no need to adjust, easy to use. Any pen can be clamped and the position can be customized. The compass has smooth lines and accurate drawing. It supports transparent square design, which makes it easier to identify right angles.