Few weeks ago fx USA will tell you that you need to send in your gun to be install by a pro for $300. A week or so ago, a member said if you call fx USA and talk to a tech and tell them you know how to take the gun apart, he can authorized a power plenum to be ship to you. I just received a email from fx USA that you do not need to ship your gun to fx or Utah airguns or even call them. Cause most time you try to call, you never get through. I try calling fx USA over 10 times, I never got a hold of a person. So I emailed them and got a confirmation that you don't need to call them. Just email them and they will send you a order form. Fill it out and send it back and they will send you a invoice. You pay it and they ship it to you.