Target training: Support. Shed Excess Water, Burn Additional Calories, Keep Muscles Warm and Limber. The Neoprene Waist Trimmer retains body heat to help you burn more calories as you work out. Made of high-quality neoprene for heat retention. Easily adjust for perfect fit. Wear over or under clothing. One size fits most. Hand washable. Benefits: The sauna-action of the waist trimmer boosts the benefits of your exercise program. Fits snugly to trim appearance around your middle instantly and support the lower back.