This mat was described as being appropriate for carpet pile up to 0.75-inch thick which should have been right for my rug that is only 0.4-inch thick. The prongs on the back of the mat are only about 1/8-inch long and consequently do not penetrate the carpet an adequate amount to keep the mat in place. The mat shifts constantly and I have to readjust it several times a day to keep it straight and under my desk. I do not recommend this mat for carpet with pile higher than 1/4-inch.