Effect: who knows? It's probably all placebo. But for me, less ear pressure even with a proper seal, so less stuffy/pressurized while same isolation if you're careful enough. Step 1: invert your IEM tip Step 2: use a hole puncher (I use one for belts that has multiple different sizes) to poke some holes in the rear end. Note: make sure to not get too close to the front as that may create a seal leak and drop bass, try to get as close to the rear as possible. You can poke as many as you like, but for me, I prefer 2 with Andromeda. Step 3: punch holes in the front part as well (I end at around 4). NoteL: again, don't get too close to the opening of the tip or you'll create a seal leakage Holes! I prefer 4 of these with Andromeda, but you can certainly poke more depending on your use. Step 4: invert them again and they should look... hacky. ...and kinda more "transparent" than before? Step 5: fit them onto your IEM and enjoy! Posting this now since I took photos and stuffs, and just in case I sleep too much next week and forget to post it. As always, happy modding, folks!