The equatorial telescope mount is aligned to the celestial pole and uses a series of gears attached to slow motion cables to track targets in right ascension and declination. Most models include manual setting circles for locating objects. Employing a counterbalance, the EQ mount design is favored for heavier telescopes and those interested in astrophotography. They allow the user to add optional drive units and digital setting circles or to purchase it as a computer-controlled "GoTo" telescope mount.
Equatorial mounts come in several different configurations. The classic style is known as the German Equatorial Mount (GEM), which somewhat resembles the letter T. One bar is the right ascension axis and the other is declination. The telescope is placed at one end of the declination axis, and an adjustable counterweight is located at the other. The right ascension axis is home to the setting circles, bearings, and gears. It is connected to the mount base and utilizes polar calibration. Large motions can be achieved by unlocking the axis, which is a practice done for general aiming. The gears are then locked down, and smaller adjustments are controlled by a set of slow motion cables. The GEM mount can be easily equipped with small motors that assist the unit in tracking celestial phenomenon. The GEM mount can even be computerized for hands-free operation.
Another style of equatorial mount is the open fork mount. Resembling a tuning fork, it is attached to the right ascension axis at the base. This design is usually favored by larger SCT-style telescopes. While it is somewhat similar to an alt-azimuth mount, the open fork mount requires a simple piece of equipment called a wedge to achieve proper angular alignment with the celestial pole. This arrangement is also well suited to computer control.