Metal round brush with natural boar bristles. The metal barrel fills with hot air from the blow dryer while the vented holes create plenty of circulation with the added bonus of the natural boar bristles, which create a lot of of tension coaxing the cuticle to lay flat for the ultimate smooth and shiny finish.
Your length of hair will determine the diameter of the round brush needed. The shorter the hair, the smaller the diameter, the more curl or bend you will get in the hair. The larger the diameter, the more fullness and "c" shaping.