The Builder's Best® 010153 Saf-T-Duct® Periscope 18-29 Dryer Vent Duct is designed for IT and facilities managers needing to optimize space in utility rooms or server environments where dryers are present. Its periscope design allows for flexible installation, with openings that can be configured on the same or opposite sides, and fittings that rotate to any position. The duct telescopes from 18 to 29 inches, accommodating various installation depths.