We have three 50 gallon water barrels. They have been with us for a long time and the caps have rotted. Now I have three barrels of water that are useless. I wasn't expecting to find caps so I was thrilled to find them. They fit well and we're back to water storage. This is important to us because we live between the two biggest earthquakes in Southern California and I don't like being without a water source in an emergency. I am very happy that I found these caps.