The Pro-curler set has 6 inter-changable tourmaline ceramic ion barrel that easily create different curling style as per your need. Barrels are in different shapes and sizes: cylinder 32mm, cylinder 25mm, cylinder 19mm, conical 18-9mm, Spiral Barrel 25mm and Bubble Barrel 25mm Tourmaline is a natural source of negative ions and far infrared heat, which provides faster styling. Negative ions eliminate frizz and close the cuticle to create smooth, shiny hair.