QR-L (FastBrake) inline quick release valve. P/N 800333, BW800333, 4000-8. NSN 4820014787296. Also replaces GTD4000-8, NSN 4730013657024.
The QR-L typically mounts on the tractor protection valve. 1/2 inch NPT pipe threads on inlet and outlet.
The quick release valve speeds up the release of air from lines and devices that it is attached to. 0 PSI crack and differential pressure. 150 PSI max inlet pressure.