TENGA Flex is a revolutionary reusable suction stroker that combines the latest engineering advancements with quality craftsmanship to provide unprecedented sensation. They feature a soft outer casing made using malleable materials molded into a spiral form to provide a just-right fit for all shapes and sizes and a strong vacuum sensation. While using the air hole, moving the FLEX cup up and down tightens and loosens the spiral, revealing new intimate sensations. Our Rocky Black Flex cup features firm, more pronounced interior details for more rugged and intense stimulation.