A flap barrier, also known as a flap gate or flap turnstile, is a type of access control mechanism commonly used in areas where there's a need to regulate the flow of people, such as in subway stations, airports, office buildings, and stadiums. It consists of a series of horizontal bars or flaps that rotate to allow or block passage. https://www.novusapl.com/flapbarrier-ultrapremium-series.php