For the days that require an extra oomph, there’s the Iron Flask 24 oz Grip Coffee Mug, which comes in a variety of colorful powder coatings for strength and style. Iron Flask’s travel coffee mugs are made with double-walled, vacuum-insulated stainless steel to keep your Ethiopian Ghimbi or London Fog nice and hot for four hours—with no mug sweat. Plus, it’s 100% leak-proof, so you never waste any of that precious, precious oomph.