Interference. A little reassurance goes a long way. 5 hours and they let so much wind noise in and if one falls out while doing 20mph you will never see it again. Its ok. Impressionnant! But it is better to use little bit more money and buy something that actually sounds good. I finally found them and I am so happy ?? they fit perfect for my feet. 3Efficiency. Osservate la foto e ve ne renderete conto subito. But no more!