Cup holders in most vehicles are made for a medium size. I don't like that much coffee! This is a sleeve for a small coffee to bring the top of the cup to the position of a medium. It also serves as a sleeve to keep the hot coffee away from my fingers for a few minutes. It is made specifically for the Tim Horton's small cup ( #10004669 2).
This model is made for cup holders in the 2015 Dodge Journey.
The inner hole is tapered to the same form as the cup. The outside is made to conform to the hand with a place for the thumb, There are also 4 tiny spheres that hold the sleeve in place. As you slide it on, give it a twist to align the thumb groove with the lid opening.
It allows you to grab the cup safely while driving.
PLA seems to work fine.
Even as the sleeve warms up there is no place for a deformation to occur.