Pololu - Sanyo Pancake Stepper Motor with Encoder: Bipolar, 200 Steps/Rev, 42×24.5mm, 3.5V, 1 A/Phase, 4000 CPR
MOONS' High Resolution Stepping Motor NEMA23 High Torque Stepper Motor 2.4Nm(340oz-in) 1.5A 2Phases 0.9deg 77mm(3.03in.) High Accuracy Smooth Quiet Step Motor (Model MS23HAAP4150) : Amazon.ca: Industrial & Scientific
What Is A Stepper Motor? | Library.AutomationDirect
M-168 High Resolution Stepper-Motor Precision Actuators