This is a modernized version of the original OPS Inc / Allen Engineering three piece collar.
These are designed to work and fit around a front sight base (FSB) that has a bayonet lug. Unlike other AE collars, these do not have a set screw to hold them in place and it will slide around on the barrel unless the suppressor is installed.
Each collar is individually serialized.
Barrel requirements to use this collar:
- Barrel needs to be 0.748" in diameter forward of the FSB
- These will work with a bayonet lug
- The barrel will require contour work so the collar fits
- It's generally best to use a 14.5" or longer barrel and have it cut down the exact final length