NonEcho Men Sauna Sweat Vest Weight Loss Waist Trainer Vest Neoprene Tank Top Shapewear Slimming Shirt Workout Suit Upgraded Size,please according our size chart which is on the last picture to choose the right size, XS-5XL available. Don't refer to the review to choose size. Neoprene slimming vest is elastic The more you sweat, the more you lose. You burn anywhere between 300-500 calories in 20 to 30 minute via sauna waist trainer and this equals 5 pounds. Slimming sweat vest helps to tighten belly and firm your abdomen Sauna vest with zipper intensifies perspiration in your core by up to 3 times more than regular gym clothing,sauna suit fits snuggly around your midsection, working its magic from your shoulders, down to your waistline, work as waist trimmer, meanwhile helps posture for back and abs as you workout 10mm Neoprene not only produce heat to make you hot and sweat like crazy when workout, but keeps your body warm during cold days with minimal thermal cover, if you work in a cold place you are able to stay warm when wearing this sauna tank top Men weight loss vest can be worn under or over any regular shirts, invisible sauna trainer vest, can't see it under your shirts when you workout please select the black one Reversible waist trainer vest for men doesnt stink too much after prolonged use, easy clean and hand washable, please hang it outside to air dry <span class="a-text-bold">Firstly</span>  by raising your core body temperature, so your body has to work far  harder to cool down and maintain a healthy temp. (this is called to  thermo regulate). This process causes the body to burn off at least 50%  more fat because of the extra energy (increased energy expenditure) your  body uses to cool down and maintain a healthy core temperature. <span class="a-text-bold">Secondly</span>  they cause the body to produce a heavy profuse sweat. To create sweat  your body uses up massive amounts of fat and energy and burns 0.7  calories for every gram you produce. Scientific testing shows an extra  300-800kcals can be used in a workout wearing a Sweatz Quick Weight Loss  Vest. This actually burns off at least twice the amount of calories and  fat, accelerating your quick weight loss to a tremendous level. <span class="a-text-bold">Thirdly</span>  they put you straight into the fat burning zone which usually takes  over 30mins. So your actually burning fat for your full workout instead  of just the average 20mins of a 1hr session. This makes fat burning 3  times more effiecient. <span class="a-text-bold">Fourthly</span>  When wearing the vest your metabolic rate is increased by roughly 30%  giving you an extra 30% more fat burn whilst working out.