Premium Quality: Made of high quality ABS and TPR, odorless, low hardness, durable and with a long service life. Non-slip: The bottom surface of the door stopper is grooved to keep the door firmly in place and prevent it from slamming or sliding. Storage Holder: Each door stopper is equipped with a specific storage holder, which can be easily stored when not in use to prevent loss. Easy to Use: A set of 4 door stops, one door stop fits a gap of 3.2 cm and 4 can be stacked together to fit a maximum gap of 12.8 cm. Stack different quantities according to different gaps. Widely Used: Effectively applied to any door on the surface of linoleum, tile, stone, wood, carpet, cement, asphalt, etc. Double stack the stoppers for use on doors with higher thresholds.