thanks I will buy the hop up pdi soon

Assembling the hop up is a real pain, but worth it all the way.
Good luck to you! Be sure to let me know how you make out.

you say that hop up is hard to install. I search on internet and I dont find video that explain how to install a pdi hop up if you know if have a place that explain this, tell me were please

It's not that it's hard to install, it's more that its a pain in the ass to assemble the hop up itself.
It does come with directions, they are enough but not exactly detailed.
This is the best I found

http://youtu.be/9YMGo-oo0gI

It's not perfect but gives a general idea.
Don't forget an aps-2 barrel WILL NOT fit in that hop up. You need a new bucking and aeg cut barrel.

I will probably take that inner barrel http://www.airsoftgi.com/product_inf...oducts_id=7579 I think its correct