8 QTY: Bracket Spacer Block/ Bracket Extension: LARGE/ Blind & shade installation Bracket Spacers for Window Treatment Installation 1 3/4" x 1" x 3/8" : Spacers may be stacked Allows for a professional looking results on even the most difficult of installations Allows you to clear moldings or compensate for openings that are not perfectly straight. A simple tool for dramatic art installation.