A 3D printed pulley is a mechanical component produced using 3D printing technology, typically from plastic or composite materials. It functions as a wheel with a grooved rim, designed to guide and support movement of a belt or cable, transferring rotational motion and force in machinery. In cybersecurity, while not directly related, 3D printed pulleys can be relevant in discussions about hardware security, as custom or counterfeit parts could introduce vulnerabilities in physical security systems or industrial control equipment. The ease of producing such components highlights the importance of securing both digital and physical aspects of modern infrastructures.