The SG90 Micro Servo Motors comes as a set of two motor modules that boasts three pairs of blades which can rotate from 0 degrees to 180 degrees. The connector wire measures 150mm in length which is sufficient to install it on a breadboard. Simply plug in the included arm and gear assortment and start experimenting for your next DIY project. 1.8 kg-cm torque means that the motor can pull a weight of 1.8kg when it is suspended at a distance of 1cm. So if you suspend a load at 0.5cm then the motor can pull a load of 3.6 kg of weight. This can be used as actuators in many robotic arms, or as a steering system in RC toys. Due to its lightweight, it can be used in multi-DOF robots like humanoids.