In leiu of a drop-in upgrade piston for the Tokyo Marui NGRS MP5 platform, we can modify the FPS Softair Carbon Fibre NGRS AK/G36 piston. 
 
We machine out the the recoil notch of the FPS piston and deburr the edges by hand. 
 
Please note this is the service charge and does not include the piston. 
Add this service along with an FPS NGRS AK/G36 piston (PM07CF) or feel free to supply your own - just put a note in the box at the checkout :)