English: A miniature electro-mechanical linear actuator manufactured by Zaber Technologies Inc (http://www.zaber.com). The specific model number is T-HLA28. This actuator utilizes a lead nut built into the rotor of a bipolar stepper motor. The lead screw is prevented from rotating. Thus as the lead nut is rotated clockwise or counter-clockwise by the motor, the lead screw is extended or retracted from the actuator. The lead screw is shown here in the retracted position, barely extending from the right end of the actuator. There are two cables attached to the actuator because it is designed to be daisy-chained with other actuators and controlled from a single serial or USB port using an adapter (not shown).