These seals were great. I am using them on a 5 gallon bucket hydroponic system. Many reviews on here suggested that they dont work with 5 gallon buckets but I decided to try anyways. They were very hard to install. I had to put the PVC through the seal before installing in the bucket. I even tried vaseline to slide the PVC in but that didn't work either. They don't leak a drop though and they did end up working. Just a little labor intensive and pricy compared to other online options.