SL SECURE: DOOR-TO-DOOR | SL TOP: DOOR-TO-DOOR SL FAST: DOOR-TO-AIRPORT | SL FLEX: DOOR-TO-AIRPORT   SL TOP: DOOR-TO-DOOR This is the ideal method for shipping extremely urgent products, offering you similar or identical transit times as available on same route for passenger transportation. SL TOP features transportation on: Lower deck capacity on scheduled quality carrier flights, whenever possible on non-stop/direct flights. If the transportation from origin to destination involves a transfer, the longest permissible transit time at transfer point is 6 hours. On-board courier. Full charter aircraft. A combination of the above.