Tressa smooth operator straightener for naturally curly hair. Effective and easy and fast.You"ll go sleek ,manageable, straight hair with beautiful , healthy results.Choose which one will be good for your hair: Normal resistant formula for virgin hair and hair treated deposit only hair color Color treated formula for hair with permanent hair color with 20 vol or above. Please don't use on bleached or over 50% highlites. Key features: Only straightener you can color and shampoo same day Clear and easy directions with step by step pictures keep things simple This based straightener has just 2 products to apply, no pre or post treatment necessary Keep same curl, make it wavy or go all the way straight multiple options and retouchable No flat ironing required no heat application No formaldehyde