It is a detonator Tokyo Marui Px4 dress-up parts.
It is a set of machined aluminum and the outer barrel.
Surface of aluminum.
Extractor is reproduced in another body, the material is steel.
Real stamp will feel "that part" has been reproduced.
For easy to assemble is not included in the site, the rail portion of the piston at the bottom is another part.
* Note * Custom parts, so the adjustment becomes necessary.
Decomposition techniques is required.