GMP Tools part 89422 is an air hose assembly with an integrated blow gun and a Chicago fitting for direct connection to a jobsite compressor. Crews use it to proof and clear duct before a fiber shot, blow out standing water and debris, and pressure-check the run so the cable does not hang up on obstructions. The four-lug Chicago fitting locks positively to compressor and manifold connections that would loosen under high-flow vibration. A practical, everyday item on any cable blowing or duct-proofing truck. Millennium part #546578.