Hot Air Pencils features full closed-loop electronic and dial-adjustable temperature control. The main barrel of the pencil is made from a piece of 1/4″ 7mm copper tubing. It has a 1/16″ brass tube with a sheath of silicone tubing that is obtained from the fuel. It works with either lead-free or traditional leaded solder alloys. It is used to remove or re-flow small surface mount devices.