Call of duty stimshot! 

its pretty fun to mess around with, good to take to airsoft games.

I enjoy flicking the cap off, I made the corners sharper than the body to give a point to flick it off.

I hope you enjoy  

assembly / print instructions,

I recommend 25 percent infill for best results, but might need to go higher on the button rod.

I also recommend to sand to make it fit better

just put a few pen springs In the inside of the body,

put the button_rod in, 

and glue body_cap to the body,

and enjoy