Heavy duty flat bottom casters: Heavy duty caster wheels rotate 360 degrees for flexible, smooth, quiet, and powerful directional changes. When the brake is engaged, the mounting plate and wheels provide reliable performance. Sturdy design: Our flat bottom brake casters are constructed from heavy-duty steel. Polyurethane casters offer the elasticity of rubber with the durability of metal, ensuring long-lasting use. Load capacity of heavy duty casters is 300 kg (75 kg per wheel). Application: These furniture casters with brakes are ideal for various indoor and industrial applications. Heavy duty wheels are rust and corrosion resistant. Suitable for use on carpet, laminate, parquet, wood, cork, tile, granite, paving, and lawn surfaces. Glides smoothly over floors, operates quietly, and helps protect flooring from scratches. Safe and secure: Features a built-in wheel lock that is easy to engage and release. Size: 50mm. Color: Black. Package quantity: 4. Note: Due to manual measurement, please allow 1-3 cm size variation. Color may vary slightly due to lighting and display differences. Actual product may differ slightly from image.