Best buy rtic ndash 30 ounce insulated tumbler the rtic ndash 30 ounce insulated tumbler is the best bargain in this lineup and it rsquo s our top pick overall the stopper actually prevents some spills and compatible accessories are easy to find this is an updated version of the rtic but the old all metal no stopper version is still available without buying and trying hellip.

Insulated tumblers work by keeping hot or cold air in and eliminating condensation and vacuum insulation gets the job done best rather than simply adding an additional double wall usually plastic or glass to a stainless steel base which may allow air to pass between them a vacuum insulated tumbler is void of h20 between the two so no.

After leaving 16 insulated tumblers full of slurpee in the front seat of a hot sedan we rsquo re convinced the hydro flask 22 ounce tumbler is the best for most people even while suffering through.