At the end of 2016, the plastic raw material unit price keep increasing continually, expecially for PVC material, increase about 60% compare to the price on June, 2016. As we all know, crude oil and steels price increase all over the world, expecially since the begginning of November. This is one of the reasons that our plastic raw material areas price also be increased. Our company will change our quotation valid time from 12 months to 1 month. And we hope our custom can start the order as soon as possible. 28th Nov., 2016 Lily