美国采购需求：办公椅、人体工学椅、转椅、主管椅、老板椅、钢制椅

I'm currently looking to replace some plastic parts on a few office chairs I purchased a while back. These chairs have proven to be very durable over the years, but unfortunately, the plastic components at both the top and bottom have recently broken. I'd love to know if it's possible to order these specific parts directly from your factory. Could you provide me with information on the availability of these plastic ends? Additionally, I'd appreciate any details on pricing and lead times for the order. It would be great to get these chairs back in working condition, as they offer excellent comfort and support. I look forward to your prompt response regarding this inquiry.