Use these Christmas light combo clips to attach C7 or C9 incandescent light strings along all types of flat roofs, brick walls, window frames, door frames, and more! They offer supreme flexibility for both residential and commercial lighting applications. Each clip features 2 sides: One side holds C7 lights, while the other side holds C9 lights. Simply attach clips with silicone, screws, or magnets (not included). Cannot be used with LED C7 or C9 light stringers.