PhidgetStepper Bipolar Stepper Motor Controller - RobotShop
Bipolar Stepper Motor Driver Board - A3967SLB Development Tool - mikroElektronika
Pololu - Tic T825 USB Multi-Interface Stepper Motor Controller
Amazon.com: Stepper Motor Driver Controller, Forward and Reverse Control Pulse Speed PLC Serial Communication, DC 5~30V/4A Universal for NEMA 17/23 Motor : Industrial & Scientific
Bi-Polar Stepper Motor Driver Kit - CK1406 | Electronic Kits
Bipolar Stepper Motor Driver, 2 phase, DC 20-30V | ATO.com