Five lines four phases,can be driven by common uln2003,can be used as connecting two phase;can be used with PCB board,direct plug and socket,easy to use on PCB board A, B, C, D four-phase LED indicates the status of the stepper motor work. 5 line 4 phase can be used for ordinary ULN2003 chip driver, connect to the 2 phase , support the development board,With convenient use, direct docking This Unipolar Stepper Motor 28-BYJ48 is provided with five wires and four coils. The center connections of the coils are tied together and usually used as the power connection. They are named unipolar steppers because power always comes in on this one pole. Stepper Motor is a type of electromagnetic device which moves in discrete steps. This has several coils, the center shaft has a series of magnets mounted on it, and the coils surrounding the shaft are alternately given current or not, creating magnetic fields which repulse or attract the magnets on the shaft, causing the motor to rotate. Stepping motor/DC motor can choose external voltage for power supply via pins Speed down stepping motor Diameter: 28mm Voltage: 5V Stepping angle: 5.625 X 1/64 Speed reduction ratio: 1/64 Colour:Photo Color Material:Metal+ABS Size:8 x 5 x 3cm Package Contents: 5 x stepper motor 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.