I had a little trouble getting the headphones right, but they include several attachments so getting the correct fit just takes a little trial and error.

The iPod short cord ear plugs fit snuggly and didn't fall out.

I love the tight fit of the triple flange plugs

I do not know if I could have achieved a good fit if my ear canals had been smaller

Last night I played around with the earbuds a bit while at home and found that the smallest earbuds were the most comfortable fit and that they had to be positioned correctly in my ear to keep the waterproof seal.