The Rigwa REX Travel Lunch Box is constructed with double-wall insulated food-grade stainless steel and non-toxic materials that will keep fresh for hours. The crystal clear Tritan lid includes a pop-top feature for an even greater air tight seal and can be opened to release pressure from hot foods. The locking latches on the side makes the lid fully leakproof. Designed for easy stacking, easily store your REX box in the fridge with other storage containers. Perfect for lunches, weekend picnics and food storage.