Call it sex-ed for the grown-up set. Townsend Enterprises -- operating through its Sinclair Intimacy Institute unit -- develops and sells instructional videos, sex toys, and related items dedicated to improving the sexual health of committed couples. Its Better Sex video series, more informational films than X-rated movies, has sold more than 4 million copies in some 30 countries. The company also sells other adult-themed films; all items are available for purchase through its Web site. Sinclair Intimacy Institute works with its advisory council of sex educators, researchers, therapists, and other experts to create its products. The company was founded in 1991.