An adjusting device having first and second extendable members includes a synchronizing mechanism for making adjustments of the first and second extendable members. Each of the first and second extendable members defines an extension axis and includes an extendable portion adjustable along the extension axis to an extended length. The synchronizing mechanism is connected to the first and second extendable members and is operable to simultaneously adjust an extended length of the first and second extendable portions such that the extended length of the first extendable portion and the extended length of the second extendable portion are substantially equal.