The designations, Reefer I and Reefer II refer to the method of raising and lowering the sail, not the size or the model. The Reefer I uses an internal halyad that cleats off at the furling drum to raise the sail. Ther Reefer II uses a locking halyard system. The boat's jib halyards is used to raise a cam activator and the sail which locks at the top of the luff extrusion. Once the sail is up the halyard and cam activator ard removed and stored away from the system.