There’s no need to replace your office chair, just replace the castors with our strong and durable 50mm nylon office chair castor which features an M11 circlip fitting. Suitable for those with a carpet flooring as these replacement office chair casters feature a plastic twin wheel which rolls smoothly on soft surfaces and isn’t appropriate for hardwood flooring. Please ensure you check the push-fit size prior to ordering. 50mm Replacement Office Chair Castor with Twin Plastic Wheel