Comply Isolation Plus Earbud Tips

I've been using these eartips for about a month now, and I like *everything* about them. Before buying, I was reading reviews and noticed that several people commented that they take more pressure to install than normal rubber eartips. That was a definite plus for me, since mine usually get pulled off by seat belts, backpack straps, etc. These are staying in place perfectly. The Sennheiser HD1 M2s already have excellent sound, and these eartips have made it even better. Sound isolation is also massively improved over the standard rubber tips. It's great to be able to listen at lower volume levels with no interference from outside sounds. They're also really comfortable, even for extended wear. Also, I really appreciate that these came in a six-pack of the same size. A lot of similar products come in pairs of multiple sizes, which is pointless once you know the size you need. With these, I can eventually use all three pairs. A few reviewers mentioned durability issues, but I haven't experienced that at all. Even if they do need to be replaced periodically, the audio and comfort improvement is well worth it. Long story short, these are a great product that I'll definitely buy again.