Use premium environmentally friendly rubber: This door stopper is made of high-quality rubber material that will not damage the floor and leaves no marks. It provides a strong grip and will not harm the door. Safe and secure to use. If the rubber door stopper gets dirty, simply clean it, wipe it dry, and reuse it for better performance. Suitable for various door gaps: Fits under most door gaps and withstands daily use without cracking. These door stoppers measure 4.83" x 1.6" x 1". They work well under doors that are 0.2" to 0.8" above the floor. For gaps higher than 0.8", you can stack two stoppers together for stronger holding power. The sloped design helps prevent doors from closing on their own. Works on multiple floor types: This door stopper is suitable for use on various surfaces including wood, cement, vinyl, tile, and carpet. The rougher the surface, the better the grip. Easy to use: Simply place the door wedge at the bottom of the door. No drilling or adhesive required. Leaves no sticky residue or marks. Ideal for use at home, school, or office, allowing easy movement between rooms without constantly opening and closing doors. Suitable for multiple bedroom doors, classrooms, or office doors. Includes free holder hook: Each door stopper comes with a free hook to hang the product on any door or wall, keeping it secure and organized, and preventing loss.