Indoor entrance mats for schools and colleges need to stand up to high levels of foot traffic. Indoor mats can either be recessed or rest on top of the walk surface. Indoor floor mats normally function as wiping mats to catch moisture from shoes. It is recommended that the floor mats be wide enough and long enough to provide a safe, nonslip entranceway. Walk off mats placed on top of the walk surface should present a low profile to minimize tripping hazards. Any walk off mats with curled edging should be removed from service. Interior mats that are recessed will usually be aluminum footgrilles, rollup mats, carpet tiles or some sort of heavy duty carpet matting.