This is amazing and easy to use, simply turn the dial from 1 to 12 and control how much gas pushes your bolt back.
You have to use a straight gas tube (available from Riflespeed). I went to a 22" barrel that requires a rifle length +2. The longest available straight gas tube is rifle +1 so I cannot use this anymore. Will fit any straight gas tube on any AR platform with a .875 (heavy) barrel profile.
$200 new.
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