✔The surface material is made of high-tech polyurethane, durable and robust, with a maximal bearing load of 397lbs each. ✔With 360º rotation, the wheel is easy to move, and the material is shockproof, protecting the floor from wear and tear. ✔Easy installation only by popping out the old casters and popping the new ones in. ✔Fashionable style caster makes your chair eye-catching. ✔75mm diameter, 11mm*24mm universal sized stem fits most office chair bases. (Pls check the wheels size of your chair to ensure it will fit before ordering). Advantages of Femor office chair casters Simply contact Femor Support, Modern & Stylish Extremely quiet Super protection from scratches and streaks High-quality Fast installation longevity Ceramic tile, wood Parquet, laminate Granite, marble Stone, concrete