This sheet set is 100% cotton with extra deep pockets, it’s machine washable and dryable.  I personally found this to be breathable and comfy, it’s great for the winter, not so much for the summer months as it is flannel.  If you are looking for a comfy sheet for the winter months then this is perfect!

I also have a king bed and a beauty rest mattress, the deep pockets on these sheets are great especially for thicker mattresses.