Fits shotguns with a 1in Barrel and a .83in mag tube with a .25in gap between the two.

Since print will be clamping the barrel, this needs to be some type of heat resistant filament

like ABS,ASA,CF-PA,GF-PA, or PC.

Uses 

-2x M5x30 socket head screws
-2x M5 Square nuts (8mm x 4mm).  

Amazon link in README.
I suggest using loctite for screws

I recommend you print all my files with 100% infill.