Mighty Mug Barware, Tumbler, Set of 2 Wont fall over when when bumped into, but lifts 100% naturally. Smartgrip function never wears out and is guaranteed to work on any smooth, flat surface (i.e. your home or boat table) Entertain with no worries of spills ruining your clothes, furniture and carpet. Avoid ruining important documents and sip around your electronics worry-free Can be used for any cold drink. Grips firmly on boats, trains and planes