Good day and thx for your value time. And this is cellen from ningde jingteng rubber industry co., ltd. We are a manufacturer of food grade plastic / rubber check valve, And we are factory specializing in the manufacture and export of them for more than six years. 1) we have profuse designs with series quality grade, we have a complete set of quality control system. 2) we have own high grade dust-free workshop. 3) our price is very competitive because we are manufactory and we are the source. Should any of these items be of interest to you, if you want to know more about our product, by the way, free sample are available. You can also come to our valve website: www.Rubbervalve.Com, and choose the existing one you require