Every Oro Sports product comes with CoolPaks™. To order extra, click here. This second generation of our Maximo™ Cooling Vest is constructed to accommodate an even wider range of body shapes and weights. The flexibility of the garment is great for sizing, and recommended only for low-level activities. There are no side seams or panels on this design. Instead, wide, tapered flaps at each backside are secured at the front of the vest to form the sides of this garments. Clever? We thought so too. We ask a lot of our engineered textiles, yet they deliver on all counts: Moisture management Antimicrobial Super lightweight Breathable Lifetime performance High-tech aesthetic No other brand matches our quality constructions or MADE in the USA commitment. Activate CoolPaks™ in warm water (only once) and insert frozen technology into the interior waterproof pockets. Unlike other coolants, our CoolPaks are segmented to allow body movements. They are FDA Approved, food-safe, long-lasting, and provide a second-to-none cooling experience. If you have questions about sizing, contact us today... even if today is Sunday. We do our best to return every call within 24 hours.