Adhesive labels are manufactured by cutting windows in an upper layer of a support web through to a lower silicon coated material. A spoiler-shaped surface on at least one side of the nozzle housing, which protrudes over the contour of the nozzle housing and tapers to a point at its free end, eliminates the need to separately lift a loose rug to be able to clean at least the border region covered by the rug. The multifocal shape corrects for near-vision centrally and far-vision peripherally.