The Yeti Rambler MagSlider 295 ml stackable insulated mug with magnetic lid is resistant and perfect for camping. The double-wall vacuum-insulated body protects your hands from hot or cold contents while keeping drinks well insulated. While the magnet on the included MagSlider™ lid adds an additional barrier of protection for keeping drinks contained and preventing heat or cold from escaping, note that this magnet component is not leakproof and will not prevent spills.