Methods and apparatus are disclosed to prefetch memory objects. The apparatus includes a base station configured to receive and transmit at least one of data on a mobile station, control information of the mobile station, schedule information on the mobile station, and control information on a communication link with at least one base station with respect to at least one base station in which a communication link is not set up through a core network. A force sensor is coupled to the conditioning body to detect a frictional force imparted to the conditioning body by the planarizing medium when the conditioning body and the planarizing medium are moved relative to each other. A second fastener is disposed on the second main panel to match the first fastener. If an electronic key is used to access the lockbox, the improved system effectively disables the electronic key during a showing, so that the electronic key cannot be used to access another lockbox until the correct dwelling key has been placed back into the lockbox. Following the conclusion of engagement between the two gear-train components, the gear ratio change is completed.