The ASI174 Mini USB2.0 Mono Guide Camera from ZWO is used during astrophotography sessions to help your computer keep your mount tracking a subject with a high degree of accuracy during a long night of imaging. It is also a capable camera in its own right for planetary imaging. The camera is outfitted with a 1936 x 1216 1/1.2" sensor and tethers to your computer via USB cable or to your mount via ST4 cable. The ASI174 Mini drops in just like a 1.25" eyepiece and focuses at the same point; it also works in a guide scope or an off-axis guider.