Faster and More Accurate: The stepper motor has increased the total speed of high torque by 15%-25% compared to traditional motors. We have upgraded the PCB inside the motor to ensure the stability of the structure of the motor and to obtain the ideal uniform rotation effect to avoid system errors and obtain precise results. Low noise: The stepper motor uses sturdy and durable metal. The perfect combination of rubber and rotor makes the inner structure more stable. This reduces vibration and noise when the motor is running. High Quality Bearing: The bearing is optimized for short and repetitive movements, and provides better disassembly and assembly for long life. This means they can save money on replacement or repair engine. Low Resistance: The stepper motor can get a lower resistance value comparing with equal torque and thick motors. This greatly increases the thermal conductivity of the motor. This effectively reduces the increase temperature. Good Quality: is a brand specializing in the development and manufacture of 3D printer accessories. Each nema 17 stepper motor has passed strict quality control from factory. Product Model: 17HS4401 (DP line). Holding torque: 420 mN.m. Motor weight: 255 g/piece. Dimensions (L x W x H): approximately 42 x 42 x 38 mm. Rated current (single phase): DC 1.5 A. Rated voltage: DC 3.6 V. Phase resistance (20): 2.4 x (115%)/phase. Phase inductance (1 kHz): 3.7 x (120%) mH/phase. Positioning torque: 15 mN.m REF. Maximum starting frequency without load: 1500 PPS. Maximum operating frequency without load: 1900 PPS. Moment of inertia: 57.3 g. Model: 17HS4401S (XH line). Holding torque: 420 mN.m. Motor weight: 255 g/piece. Dimensions (L x W x H): approximately 42 x 42 x 38 mm. Rated current (single phase): DC 1.5 A. Rated voltage: DC 3.6 V. Phase resistance (20): 2.4 x (115%)/phase. Phase inductance (1 kHz): 3.7 x (120%) mH/phase. Positioning torque: 15 mN.m REF. Maximum starting frequency without load: 1500 PPS. Maximum operating frequency without load: 1900 PPS. Moment of inertia: 57.3 g. Model: 17HS4023 (XH-Line). Holding torque: 130 mN.m. Motor weight: 132 g/piece. Dimensions (L x W x H): approximately 42 x 42 x 23.5 mm. Rated current (single phase): DC 1.0A Rated voltage: DC 4.1V Phase resistance (20): 4.1 x (110%)/phase. Phase inductance (1 kHz): 4.1 x (120%) mH/phase. Positioning torque: 20 mN.m REF.