The Genius Body Brace System is available as a single or twin system. They can be used in the normal way as with any inertia reel seat belt, but for elderly or special needs passengers who need extra upper body support, the Body brace System comes into its own. When the seat belt is pulled all the way out a ratchet mechanism is activated. This means that once the passenger is wearing the seat belt it is locked, no more webbing can be extracted from the reel until the seat belt has been fully retracted, thus giving upper body support similar to that of a full harness.