Is a mask or helmet in the way?
Swap out your buffer tube with the adapter and drop it down 20mm, Enough for most optics and scopes.
They are created from high-strength SLS nylon with included Marine grade stainless steel hardware.
Simple installation, remove your old buffer tube. Keep the detent spring safe! You will need it.
Screw in the insert and feed through your fcu cable. Slide fcu cable through the drop stock and tighten the bolt until snug, do not over-tighten.
Attach the Original buffer tube onto the adapter and tighten it until snug.