Commando Products Chalk Holder Clear Anodized Handle with Standard School Chalk Professional quality chalk holder for school, office, meeting room and industrial use Pen size 1/2" x 4-1/4" with attractive 1/2" diameter anodized aluminum body with pocket clip Built-in chuck positions and firmly holds standard 3/8" school chalk and helps prevent broken chalk All machined parts are plated or made of materials to help prevent rust & corrosion Limited lifetime warranty on USA made handle - see warranty details