High torque: With high-quality materials, the motor kit has high torque (40Ncm (56.2oz.in)), low self-inductance reactance and responsiveness to avoid system errors. Uniform speed, no lost step: motor enhanced PCB board and unique stator technology, to uniform polishing of the stator gear of the motor, high precision of the inner hole, stable and accurate processing speed. Wide range of applications: This small motor can be used in fields, such as stage lighting; engraving; textile machinery; equipment; placement machine; non-standard equipment; 3D printer; automation equipment. Stable speed, low noise: for Kossel, Prusa 13, Ultmaker, and other motors have high stability. The motor has high stability, uniform speed and low noise. The inner rotor of stepper motor kit, rotor rubber covered rotor, effectively reduces noise. The structure is stable and will not get stuck: the of the rotor of the motor is coated with epoxy resin. The rotor is integrally sealed and cured by high temperature. The long-term use of the motor is also stable and does not pose a risk of jamming. Type: 3D printer accessories Step angle accuracy: + - 5% (full step, no load) Resistance accuracy: + - 10% Inductance accuracy: + - 20% Temperature rise: maximum 80deg (rated current, 2 phases) Ambient temperature: 20deg~ + 50deg Insulation resistance: 100M Min, 500VDC Insulation strength: 500VAC one minute colour:Black Material:metal size:38 x 42mm Package Contents: 3 x Motors 3 x lines Only the above package content, other products are not included. Note: Light and different displays may cause the color of the item in the picture a little different from the real thing. The measurement allowed error is +/- 1-3cm.