Cotton Inners are a thin cotton glove that is worn inside boxing gloves, MMA mitts or any type of glove to absorb any sweat. Due to sweat being acidic, it will deteriorate and eat away any glove no matter if it is genuine leather or a synthetic material. This is why an inner is so incredibly important to wear whenever you are wearing a glove and sweating. Many group exercise classes share gloves through the day so having your own Inners is much more hygienic than wearing other gloves that have been sweated in by other people. Inners do not have to fit snug as the glove that you wear will be sized and hold them in place.