I LOVE the double walled coffee mugs!  They "assist" the coffee to remain warmer for longer.  I still warm the creamer.  Left unattended, the coffee will still get cold, so don't do that!.   They go in dishwasher and microwave.  Be aware, they are glass, so they will and do break.  Be mindful they are fragile...because they are quality they are not cheap...so "enjoy with caution".  Yes, I will buy again.