I love this asa, it's soooo much better than the stock ION duckbill! Its very light andthe fack that I dont have to unscrew my tank halfway, take off my hopper and then dryfire just to degass was a pain in the a$$ (hey that rhymes!) now just unscrew a knob and the whole system is bled! It's also very nice that you don't have to buy a rail, because it comes with one. My tank sits much farther forward, and my tank was pretty long to begin with, not to mention the stock asa ads about two inches to how far back your tank is, this one sits right under the grip, which has made my marker considerably nicer to shoulder. Installation was pretty easy, unscrew the stock asa, put some teflon tape on the threads screw on the new one. Put teflon tape on the the round screw type thing and screw it into the hole you're not using, put it on the rail and you're done.
An affordable quality upgrade that works very well, If you're still using the stock asa you should really get one of these.