This inflator gauge kit includes everything you need to give your Milton® inflator gauge a complete overhaul. Kit includes 1 cartridge kit #507A, 1 valve kit #512A, 1 viewing window repair kit #506-79A, 1 inlet screen and 1 cartridge nut. Can be used to repair Milton® inflator gauges #08-A1-501, # 98-A1-501, #501, #502, #503, #S-504, #S-505, #S-506®, S-516®, #517, #518, #552, #553 and #556.