funny that video when he picks the tile up and it says 100% coverage its not the same tile that is placed on the adhesive bed , the tile they pick up has adhesive on the back of it and there is adhesive on the floor but its not 100% contact as you can see the adhesive ribs full contact 100% coverage would mean no ribs of adhesive and all air from under the tile released ,they are good trowels but it the method of fixing and consistency of the adhesive that gives full coverage not the trowel notch