It seems like you're referring to a "turnstile flap barrier." Turnstile flap barriers are commonly used in access control systems to regulate the flow of people in and out of a restricted area. These barriers typically consist of horizontal swinging arms (flaps) that rotate in one direction to allow passage when a valid credential is presented, such as a keycard or RFID badge. https://www.novusapl.com/Fully-automatic-Flap-Barrier-NS-FS1-V31D1-2.php