Product Description: Stepper Motor Diameter: 8 Mm Height: 8.2 Mm Type: Two-Phase Four-Wire Long Axis (Blue: A +, Black: A-. Red: B +, White: B-) Short-Axis (Purple: A +, Yellow: B-. Orange: B +, Green: B-) Phase Internal Resistance: 39.2 Ohms 6 V Short-Circuit Current: 0.14 A (Estimated Phase Voltage Is 5V-6V, Driving Current Is About 0.12A) Output Shaft Diameter: 1.5 Mm Output Shaft Length: Long Axis 4Mm, Short Axis 3.5Mm. Outer Diameter Of Copper Gear: 2.2 Mm (9 Teeth, 0.2 Modulus) Shipping List: 10 Pairs Of 8Mm Two-Phase Four-Wire Stepper Motors