These two phase hybrid stepper motors are optimized for microstepping and give a good fit to the TRINAMIC family of motor controllers and drivers. They are all used in the 42mm PANdrive™ family. The QSH4218-35-10-027, QSH4218-41-10-035 and QSH4218-51-10-049 are motors with 1A RMS coil current. The QSH4218-47-28-40 is different: It is designed for 2.8A RMS coil current to provide maximum torque at high velocities.
Symmetry Electronics (and its e-commerce division: SemiconductorStore.com) is an authorized Trinamic distributor.