100 Days After-Sales Guarantee:TUNNY is committed to bringing high quality door stop customers, if there is any quality problem within 100 days, we will replace it or give we will replace it High Quality Zinc alloy : It's made of premium Zinc alloy, durable and functional. Surface black treatment to form an anti-oxidation layer, effectively prevent rust off paint, [What's included]: 1 door stop ,3 Flat head self-tapping screw (0.98"(~25mm)),1 Expandable rubber stopper(1.2"(31mm)） Each door stop has its own packaging, effectively preventing collisions and scratches. Installation mode: Fix the base to the door with screws1 Tighten the screw, insert it into the base to adjust the position up and down, and then tighten the screw 3. Fix the base to the ground with screws or glue Attach decorative cover plate Wall and Door protectors: Hydraulic door stops prevent your hated door from slamming shut. Prevent doorknobs from damaging and scratching walls. Also, keep the air circulating to free your hands when carrying things. Wall and Door protectors: Hydraulic door stops prevent your hated door from slamming shut. Prevent doorknobs from damaging and scratching walls. Also, keep the air circulating to free your hands when carrying things.