I have been using my hearphone for quite a while. I have tried all three sizes of ear buds and none of them is neither comfortable nor stays put. Even the smalles size keeps popping out of my left year. I watched the video for proper insertion but it did not help. It will not stay put for more than 15 minutes and has to be pushed and twisted again and again.
I wish there was a bone conduction model available for hearphone as well.