The carriage is what houses the “brains and muscles” of the stairlift. The motor gearbox, electronics, most of the safety switches and the batteries are within the carriage. It is basically the hood of your car where the engine is kept. Stannah stairlifts use a rack and pinion gear system. Call now for a free no-obligation in-home evaluation with a guaranteed price in writing 888 532-3834 (Click To Call).