This is a vintage Durolite mechanical pencil made in the United States. It has a continuous twist mechanism and a retractable tip. The pencil uses 0.5mm HB lead and features an auto-feed mechanism and a twist-extend eraser. It also comes with an extra lead container. This pencil is rare and hard to find. GREAT WORKING CONDITION! COMES WITH AN EXTRA CONTAINER OF LEAD. HALF FULL.