A turnstile is a type of gate that makes it possible to control entry and exit into and out of a specific location. A traditional turnstile consists of a set of 3 arms that extend horizontally from a post to act as a barrier to entry. These arms either rotate mechanically to allow entry or lock to restrict access. A turnstile can provide security, organize crowds, prevent losses from theft, and control access. Security turnstiles always feature some form of barrier to stop unauthorized patrons from entering. These barriers are often composed of solid steel arms or even thick glass panes. In most high-security installments, facilities use turnstiles with steel arms because of their durability and resilience.