I use this diffuser with my Shishabucks Cloud Mini and it works wonderfully. Much better than the stock one, and better than the old silicone diffuser I previously used. Does what it's supposed to, and can't complain for the price either!
Firstly, we all know how loud open downstems can be, especially on the regal..
This diffuser, was like putting a silencer on a .50 cal. Like, why wouldn't you ;-) it was quiet what seemed like a whisper. I HIGHLY recommend for those pipes that don't have a diffuser.
As well, it comes with 3 attachments that fit snug on whatever diameter sized downstem your hookah comes with, and the fact that it's silicone, means its safe to clean, and lasts long.