Double-wall glasses have two advantages compared to standard single-wall glasses: You can hold hot drinks without a handle and condensation does not form with cold beverages. Hot drinks retain their heat longer and cold drinks remain colder than with single-wall glasses.
These Canteen tumblers are a reinvention of the paper beaker, probably the most used shape of all drinking vessels. Only here it is re-interpreted as a double-wall glass. The intrinsic function of this most simple tumbler format has been taken to a higher level.
One can imagine that whoever invented stemmed glasses was inspired by the concept of allowing the wine to "float", in the air. These double-walled drinking glasses take an alternative approach – but still allow the drink to float.