Each pencil is loaded with a 1.3mm HB lead. The mechanism works by pushing the end of the pencil. This opens a claw at the other end so you can adjust the length, or refill. It is fiendishly simple. This is my preferred drawing pencil. Great for inside a purse, or for travel. Antique. From France. Please describe the pencil you would like (from left to right, for example.) 3.5 to 4.5 inches. This is for the second and third from the right.