They're intended to be printed in TPU. I've had success with hardnesses 95a and above, but that will vary with your hardware.
For the plain koozie:
At a 0.4mm linewidth, print the part with two walls and no infill. Set your bottom and top layers to give you a thickness of 2mm. That will insure that the tob and bottom rim are solid and that the hinge on the bottom will print correctly.
For the branded versions:
The top/bottom layer thickness runs into some trouble in the shield and logo area. To get around this I followed the instructions here: https://youtu.be/su_m5zV9rvA?t=123
Using the technique in the video above I created 2mm tall areas at the top and the bottom of the model that had custom settings to print at 100% infill. Outside of those two areas printing with two walls and no infill worked just fine.