The servo can rotate approximately 180 degrees (90 in each direction) and works just like the standard kinds but smaller. You can use any servo code, hardware, or library to control these servos. Good for beginners who want to make stuff move without building a motor controller with feedback & gearbox, especially si (arms) and hardware. The TowerPro MG90S now features digital processing for greater precision. Same great performance, now with digital precision.