This Jakar 165mm long, giant Bow Compass comes with an extension arm / bar so that you can draw large circles as well as small ones. This is ideal for drafting and design work.
It also comes with a pen adapter so that you can produce circles using your technical pen / fineliner and it comes with extra leads. It has a micromatic adjustment, which makes getting the right size cirlce a lot easier.
This Compass is double knee jointed and comes in a tidy plastic case. It is a high quality compass that is made from solid brass that is nickel plated - this will produce more accurate and precise circles as the weight of this compass means it doesn't slip so easily on the paper surface.