Lots of vehicles intended for off-road use have a double gearbox — in addiiton to the standard 4- or 5-speed gearbox as found on ordinary cars, they have a second box that lets you select 'high' or 'low' ratios; you would use 'high' (= higher speed for same engine revs i any given gear) for on-road driving, for example, but might well use 'low' for off-road — lower speeds but greater power.

The use of 'switches' suggests that this is some kind of elecronically-controlled gearbox — old Land Rovers used just to have 2 gear sticks!