An ST Pigtail is a type of fiber optic pigtail that has an ST (Straight Tip) connector attached at one end which is known for its bayonet-style locking mechanism for easy insertion and removal. Typically used to connect fiber optic cables to network equipment, patch panels and are commonly used in telecom networks, data centers, fiber-optic splicing, and network junctions. Although often used in older installations but can still be found in systems that require the secure, reliable connection of fiber optic cables.