The included fin/tips do indeed fit perfectly, but they gave too good of a seal and my eardrums felt like a plunger was being used.. so, swapped to Comply tips.

They stay in my ear shockingly well (using the around-the-ear configuration) sound perfectly good, and are great for getting me through treadmill season until I can get outside again, where I run without music

These are some of the best sounding headphones that I have ever used.

Once you learn it's quirks, the FREEDOM 2 is easily one of the better wireless bluetooth headsets I've used.