This is a replacement regulator assembly for the Templar Scythe and Acr. The standard pressure regulator will work with almost all barrel conversions while the low pressure regulator vents more gas out when shooting suppressed.
If you are running a high amount of 5.56 and showing signs of being overgassed when shooting suppressed the low pressure regulator might work better for you. This regulator is the recommended regulator for 7.62×39 conversions.
Unless specifically stated otherwise the standard pressure regulator is what all Templar builds is tuned for.