A solid oxide fuel cell system comprising at least one fuel cell and at least one gas flow channel to deliver a reactant mixture. An exposure amount of the folding roller with respect to the sheet can be varied by adjusting the position of the guide member through the position adjustment unit. The apparatus also includes a head restraint control assembly having an actuator, a lock mechanism, and a lock mechanism resetting device. This allows the invention to operate without interfering with potential sound sources as well as allows for numerous deployment methods. At least one of the plurality of apertures receives a locking pin therethrough that removably couples the plastic shaft to the vehicle hitch receiver.