These horizontal drinking nipples for chickens are of the highest quality and I guarantee them to not leak. I have tried many different manufacturers of poultry drinking nipples and so many were absolute junk. Usually about 30-40% of the cheaply made nipples would leak after testing with water! Well, I finally found a manufacturer where leaking not an issue. These are the only nipples we use in our Smart Waterers, and I cannot begin to tell you how happy I am that we are working with this manufacure!