The JMW500 is the big brother to the JMW350. The Thermos Nissan Leak-Proof Backpack bottle is a cross between a travel tumbler and a briefcase thermos bottle. The slender compact size fits in backpack, duffel bag or purse. Leak-proof for no-spill transport. To drink, simply press the button. The easy opening push-button lid is spring loaded and pops up, uncovering the sipping hole. Always cool to touch with hot liquids inside. Exterior stays condensation free with cold liquids inside. Made of dent resistant and unbreakable stainless steel. Whether you are looking for a stainless travel coffee mug or a vacuum insulated thermos bottle, the JMW500 is a great choice.