23mm mics are a tight fit, but they will go in. Smaller mics fit easily. They're heavy-duty, and nicely made. I put a little nose grease on the rubber before I slid them it, and that helped. If you're careful, you shouldn't touch the metal at all. Overall, I can't imagine how you could make them better. Whether they do the job in the most extreme situation, I don't know--more space for the suspension would theoretically provide more isolation. But it is nice having something so compact. Like the others mentioned, dealing with aaudio was completely smooth.