You can also get the Modify spring guide. A bit cheaper and it is the same overall.

They also usually have the MASK piston heads...

Here:
http://www.airsoftparts.ca/store2/in...oducts_id=1184

Also, you might want to install that head instead to reduce the impact. It is made to be used with the MASK piston head:
http://www.airsoftparts.ca/store2/in...oducts_id=1318

Yes, Yes they are :)
Hit me up if you want me to get some for ya :Shameless Plug: :D

Hah, if i ever try to re-build my G36, You will hear from me,

Thanks :)