The Standard SIM, also known as a Regular SIM, is a type of Subscriber Identity Module (SIM) card used in mobile devices. This card stores data that identifies and authenticates the user's mobile device on a cellular network, and has been around since the late 1990s. The Standard SIM measures 25 mm by 15 mm, making it larger than the Micro and Nano SIM cards that are commonly used in newer mobile devices. It contains the necessary information to connect to a mobile network, including a unique serial number, mobile number, security authentication and ciphering information, temporary information related to the local network, a list of the services the user has access to and two passwords (a personal identification number (PIN) for ordinary use and a personal unblocking code (PUK) for PIN unlocking). Standard SIM cards are rarely seen in modern circulation.