This trailer emergency knob fits Mack and Navistar trucks and includes a spiral pin for installation. Pulling the knob applies the trailer air brakes manually and cuts off supply air from the tractor, holding the trailer in place for parking or emergencies. It is sold individually, one each.Interchanges:Navistar 463505C1Mack 745-248600LVK-1373FeaturesTrailer emergency knobIncludes spiral pin, part number LPN-5119 (OEM 31AX629)Sold pack: 1 eachCategory: Air Brake PartsTech SpecsSell pack: 1 EACHKit includes: Trailer Emergency Knob (LVK-1373-001) and Spiral Pin (LPN-5119, OEM 31AX629)