I feel very sorry for the inconvenience caused. Can you refer to the attached official document as example (this is the document coming together with the materials we delivered to you recently). There is a storage temperature indication (I screenshot the portion as below). In addition, as you can see on the sales spec, we warrantee the material property within spec limit until end of shelf life, which implies that the shipment condition should not be a concern to us because we have to ship anyway. And, as explained previously, we don't have much choice if we have to keep such low temperature during shipment. So we use dry ice, which is possible make the temperature lower than -20C. so we have to relying on the dry ice to keep the material to the low temperature during shipment. However, we have always been using dry ice for many years for shipment, and with many materials shipped to customer. So this has been our practice and we believe it will not cause problem because otherwise, it should have frequently caused problems for many materials.