Here is disclosed a stopper for stopping the upward movement of a bottom bar attached to a fabric blind wound on a roller tube mounted within an elongated chamber of an elongated housing having a vertical wall. The stopper includes an elongated member having a head portion, a toe portion and a neck portion between the head and toe portion. The head portion is mountable within a mounting cavity positioned on the elongated housing adjacent the vertical wall. The mounting cavity, head portion and neck portion are dimensioned and configured to position the toe portion between the vertical wall and the roller tube when the stopper is mounted to the housing. The toe portion has a multi-position spacer element for selectively positioning the toe portion between proximate and distal positions relative to the vertical wall.