I bought this dab rig back in 2015 at ELEV8 Glass Galleries in Colorado Springs. To this day, I've not seen any others like it. She's been my daily driver ever since. The glass is plenty thick, I've clinked and clanked it about during cleanings and nothing has ever chipped or cracked, she looks as good as the day I bought her, except the graphics are starting to fade a bit.
Here is a macro shot of the double mushroom perc. If you look close, you can see that there are slits on the inner mushroom as well as the outer. The resulting chug is smooth and easy, producing a ton of vapor cooling bubbles.
Another look at the double mushies
This last April 20th, they had a glass sale going on and I thought about buying a new rig and retiring this one, but in the end I just couldn't do it. She's just too fun to change out. 
When I bought this I paid about $150.00, which is a lot of money to spend on one pipe, that said, it has lasted me 3 years and I'm sure she will live on for many more years to come. If you are in the market for a new glass piece, make sure you check out your local shops before buying online, there are a lot of amazing artists in just about every city and you might just find something perfectly you instead of something that just works. Support your local glass blowers!