So I am watching The Expanse on Syfy, the EVA Suit, I want it. I am going to start a project, step by step and update as I go. I really want to make a replica because it looks so cool. As of now I have identified one of the MCRN, Martian weapons used in the show. It is an ECHO 1 MTC3 Airsoft Gun with slight modifications, but just from looking at the rifle I am pretty sure it is the same model. I am new to this so this will be updated as it progresses, if I got the wrong gun used as the base for the prop then call me out and an edit will be issued.
MCRN Rifle:

And this is the Echo 1 MTC 3.

At this moment I am currently taking taking measurements for the Helmet of the EVA Suit. I am comparing actors height and trying to use scale/reference objects to find accurate dimensions of the helmet.
MCRN Rifle:

And this is the Echo 1 MTC 3.

At this moment I am currently taking taking measurements for the Helmet of the EVA Suit. I am comparing actors height and trying to use scale/reference objects to find accurate dimensions of the helmet.