gt4dPage 1 • All of the units included in the MHC-GT4D (SS- 4D (SS- GT4DB, SA-WGT4D, Remote control) are required required to confi rming operation of SS-GT4DB. Check in Check inGT4 Baggage Tow Tractor features automatic transmission, front wheel power steering,rear wheel drive and four-wheel hydraulic brake. It is desned expressly to meet demanding