These tools are used by custom Hat Makers to form the “Kettle” & “Pencil” curl in a hat brim, typically a Western Style Cowboy Hat. But, this type of curling iron can also be used on Fedoras, & Lady’s Millinery Hats. Curling the brim of a hat is not hard if you have the right tools & some experience. To see a video of this process, go here Built-To-Order, Hat Making Tool, Kettle Pencil Curl Brim, Four | 4 Piece Set, Half Circle Shackles, | Dia. 0.375", 0.50", 0.625", 0.75"