Milton 522 Bayonet Gage with Dial (truck) Head Chuck BOWES MIL 522. The first single replacement cartridge air line gage. Valve and gage COMBINED IN 1 replacement cartridge. Lever action, heavy duty construction provides long service life even with constant use. Large Black numbers on “jumbo” white nylon indicator bar for LBS, and large Red numbers for kPa. 2 sides are calibrated from 10-120 lbs in 2 lb