I'm really pleased with the covers because of the material, the solidity and the resistance of the zippers. The covers are quite practical to put on the mattress. A small negative point that may be important: I ordered 2 covers, one had the seams of waves in width, the other in length and the logo was not located in the same direction or in the same place.
Otherwise the rest is perfect, the covers even added firmness to my latex mattresses that I found too soft.