AMPERSAND 8-Ft. / 9-Ft. 8-Rib Wooden Outdoor Patio Umbrella Solar-Powered 40-LED String Lights (Cool White) Solar-powered; no electricity required! Super bright LED lights that are energy-efficient Comes with an "on/off" switch Latest improved solar panel, high conversion rate and long lasting Dimension of each rib: 1/2" W x 9/10" H (13 mm x 23 mm) ***Designed for patio umbrellas with "square" ribs***