Emergency Locking Retractor (ELR) function allows the occupant to have free movement while buckled up, but in an emergency situation or crash the retractor instantly locks securing the occupant. This is accomplished by an inertia reel with which all of our retractable replacement seat belts are equipped. The inertia reel is "webbing sensitive," meaning that any sudden movement of the webbing (the seat belt strap) causes the retractor to instantly lock