Inside or outside, this is sure to become your favorite daily drinking tumbler! Triple-insulated stainless steel will keep your drink cold for up to 9 hours, even in the sun! That's more than twice what you'll get from a plastic tumbler! Keeps your tea or coffee hot for up to 3 hours too! Includes shatterproof plastic lid designed to be sipped through and spill resistant. Easy-grip flat sides and no-slip bottom means this tumbler will stay where you put it. Built in slider is easy to use and when closed between sips help the tumbler maintain temperatures.