The Powerbeats are a great improvement in snorkeling. I use them for lap swimming and ocean snorkeling here on Maui. Initially there was leakage in the membrane in the tubes so I ordered the longer tubes. I stopped the leakage, which was only resulting in noise with exhale, With a small amount of silicone I use for other dive equipment. So now I have two different size tubes. The delivery from Germany did take six weeks, but I had fixed the originals. Highly recommend the powerbreather.