This is popular geared Nema 17 stepper motor with a medium body and torque. It has an integrated planetary gearbox with a 5.18:1 gear ratio, the resolution reach 0.35°step angle. It's a good solution in applications that need very low rotation speeds and/or lots of torque.Electrical Specification* Manufacturer Part Number: 17HS15-1684S-PG5* Motor Type: Bipolar Stepper* Step Angle: 0.35°* Holding Torque: 1.68Nm* Rated Current/phase: 1.68A* Phase Resistance: 1.65ohms* Recommended Voltage: 12-24V* Inductance : 3.2mH±20%(1KHz)Gearbox Specifications* Gearbox Type: Planetary* Gear Ratio : 5.18:1* Efficiency: 90%* Backlash at No-load : <=1°* Max.Permissible Torque: 2Nm(283oz-in)* Moment Permissible Torque: 4Nm(566oz-in)* Shaft Maximum Axial Load: 50N* Shaft Maximum Radial Load : 100NPhysical Specifications * Frame Size: 42 x 42mm* Motor Length: 40mm* Gearbox Length: 27.3mm* Shaft Diameter: ?8mm* Shaft Length: 20mm* D-cut Length: 15mm* Number of Leads: 4* Lead Length: 500mm* Weight : 460gConnection:Black(A+), Green(A-), Red(B+), Blue(B-)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.