Waist trainer: Grab yourself a 2-in-1 vest and waist trainer. Effective: Helps in sweat production while exercising to promote additional calorie burn! Colour options: Choose from either black or grey. Material: Made of a blend of breathable 70% neoprene, 15% polyester and 15% nylon. Size options: Choose from 5 sizes - see full details for guide. Mens' 2-In-1 Vest & Waist Trainer | Black | Living Social