DC Gear Motor 12V 100RPM, Micro Motors 1.5"(37mm) Diameter built-in Gearbox DIY Motor, Respooler Motor This is a 12V DC Motor : geared motor with a built-in gearbox, metal gears, sturdy and durable, stable and reliable, primarily used in respoolers, 3D printers, DIY projects, student technology projects, and antenna rotors.