Yep, PacBrake actually designed the 4, & 5" in line brakes for some truck applications that can't run an engine brake... . they factory calibrate them for the correct back pressure based on the specifications of the engine manufacture and forward them to the customer, or some of the distributors carry them on the shelf with different calibrations.
The adapter on the turbo side is usually welded to the pipe so that there is no leakage...
They can be tied to the ECM like the direct mount, or ran manually. .