424AS, 424DL, 424FW, 424PTO, 424TCDF, 424TCDR

424AS          Air Suspension

424DL          Differential Lock

424FW         Fifth Wheel

424PTO       Power Take Off

424TCDF     Traction Control differential front

424TCDR     Traction Control differential rear

Fits: Freightliner, Peterbilt 2000 & older, International 9900 

All chromed plastic