Office Chair Base 28’ Swivel Chair Base Heavy Duty 350 Pounds Replacement High-quality Material Office Seat Plate Premium Tube Smooth & Quiet Rolling Comfortable & Ergonomic Design Our Advantages Load capacity: 350 lbs (cylinder rated); 320 lbs (seat plate rated); 110 lbs (caster rated),Adjustable height of cylinder: 100 mm/4 inch, Wheel casters diameter: 60 mm (2.4 inch),Product weight: 22 lbs, Base size: 28’,Color: Black, Material: Metal/Plastic, Mounting hole pattern: 6’ x 10’ / 15.2 x 25.3 cm