Spherical domes are the most popular type of domes in the world. The spherical domes designed by IPTEC are three sizes with an inner diameter of 7.5, 8.5 and 9.5 meters. The shutter type is the longitudinal sliding with a width of 2.4, 2.8 and 3.2 meters (respectively). The angular aperture of the shutter has a range of -15° to 105°, which allows the telescope to observe from horizon to zenith. The dome power transmission is a 0.01-degree precision gearbox and the shutter power transmission is also a gear type.

The small shutter in these domes has the task of preventing wind-induced disturbances and the light entry from the surrounding environment into the dome space. The sliding motion of this shutter enables it to be positioned at any desired altitude position and to operate at all times of the observation, whether at zenith or horizon.