Top-grade four-circuit air brake repair kit is well compatible with MAN trucks, covering cross reference numbers 9347140100, WG9000360366/4 and 81521516082. The package comes with complete fittings to overhaul and fix the four-circuit protection valve. It is built with sturdy wear-resistant and airtight materials, which can recover steady pneumatic performance and extend overall service life. Built in line with official OEM standards, it serves as a reliable aftermarket choice for daily upkeep and breakdown repairs. .