FYSETC is a professional supplier of 3D Printers related accessories products. It has a professional R&D team and high quality after-sales service to ensure that you can enjoy your shopping. Specifications: Model Type: MS17HD4P484A-01 Condition: 100% brand new Number of phase: 2 Step angle: 1.8 degree Rated Voltage: 4.83 V DC Rated Current: 0.84A Holding Torque: 0.35 Nm Typ.(Two phase on/rated current) Phase Resistance: 5.75 ohm±10%(20℃） Phase Inductance: 8.4mH±20%(1kHz 1V rms) Rotor Inertia: 38 g.cm2 Motor Weight: 0.22 kg Insulation Class: B(130℃) Connection: Yellow(A+), Green(A-), Red(B+), Blue(B-)What the steps/rev are for this stepper motor? please see the below formula: E-Steps-per-MM=(Motor Steps * Micro-stepping*Gear Ratio) / (Hobb Diameter*π) Standard motor steps / rev =200 Standard micro-stepping = 16x Gear Ratio = 3 Hobb Diameter (Effective)= 7.3 Warning: Make sure the motor connect to a constant current or chopper drive controller before you test motor. Connecting the motor directly to a power supply will destroy the motor. Package Included: 1 x 42-34 Nema 17 Stepper Motor 1 x 39.3 in Cable