A fidget chain is a small, handheld device designed to help people focus, relieve stress, or keep their hands busy. It's typically made of interlocking metal rings or bike chain links that can be flipped, twisted, or manipulated in various ways. The repetitive motion and tactile feedback provided by the chain can be soothing and help improve concentration. Fidget chains are compact and quiet, making them suitable for use in classrooms, offices, or other environments where more noticeable fidget toys might be disruptive. They're popular among individuals with ADHD, anxiety, or anyone who benefits from keeping their hands occupied.