Instrument Clinic Tan leather clarinet are high quality! Pads over 21.0mm have a rivet. Thickness: ~3.5mm Please email your pad diameters when you checkout via Amazon message system. If we dont receive size info within 4 hours of purchase, we will send a "universal" set. If you need to exchange pads for a different size after the kit has been shipped, we will make the change, no problem. However, we do charge a fee to cover the postage for the exchange.