Material: these furniture leveling screws are made of metal and rubber, more toughness, longevity and corrosion resistance, anti-rust, the screw thread is deep which is not easy to slip during rotation and not fall off easily. No more scratches: This product has a round base, smooth surface without burrs, exquisite workmanship. Thick base, strong and stable, the round rubber base will not harm or scratch the floor. No Squealing: These leveling feet are a solution for uneven table legs, you can install them at the bottom of your product to stay balanced, also as a bonus sound dampening floor protector mat, your furniture will glide quietly and easily without squeaking. Height Adjustment: Using this product, you can adjust the height of the table and stool according to your preferences to meet your daily needs. The minimum height is 8mm and the maximum height is 20mm when installed. Package Included: 22 Pack Adjustable Leveling Feet for Furniture Legs, the size of this product is M8 x 20mm .