Style it out Mini thermal hairbrush 33mm barrel Ideal for adding shape and volume to shorter hair Copper-coated barrel heats faster when used with your hairdryer for a salon-smooth finish Designed to be used on detangled hair Take care not to wrap hair all the way around brush. The copper coated barrel heats faster with your dryer, leaving the hair with a salon smooth finish. The 33mm barrel is to be used to blow-dry knot free hair, take care not to fully wrap hair around the brush. he 33mm barrel is to be used when the hair is knot free.