Makeblock 57BYG Stepper Motor has higher torque and better response speed than 42 stepper motor.  With Makeblock 57BYG Stepper Motor Bracket, they may be easy to connect to Makeblock structural components.
Fetures:
? high output torque
? low noise
? low power consumption
Specifiations:
Weight: 700 g
Motor length?? 56mm
Output shaft length?? 8mm D shaft
Pin count: 4 
Step Angle (degrees) :1.8?? 
Holding Torque : 1.2N.m
Phase current : 2.8A