I got these to replace the original ear cups that were falling apart and the vinyl was peeling. These are significantly lighter, and WAY more breathable. Since they are very lightweight with a medium-ish density foam and are fabric covered, they DO NOT isolate sound like the vinyl cups, you will hear the world around you, but for me this is ideal because I now I can hear the cat yelling when he's locked himself in the laundry room again without taking them off lol. They're doing what I need them to do, and don't make the arms of my glasses hurt my head or shed black flecks all over my face. Not difficult to install, you just have to take it slow and be patient, whatever JBL uses for adhesive is pretty strong! Try wearing your old cups for a song or two to warm them up and soften the adhesive a little if it's giving you extra trouble. All in all, A+ for under twenty bucks,