Abstract: A plastic skylight having a central dome and a pair of standing seam edges is suitable for installation in metal standing seam roofs and shingled roofs without a curb. The standing seam edges are joined to adjacent metal standing seams with the same covered by battens. The other edges of the skylight form flat flanges overlapping adjacent metal panels. When used on a shingled roof, step flashings and anchor clips are fastened to the plastic standing seams. The skylights may be clustered to form sunroofs.