The Skywatcher Skyliner 150p Dobsonian Telescope 153mm/1200mm (6") is the smallest in the range and has a "paraboloidal" primary mirror to eliminate spherical aberration and a four-arm, secondary- mirror bracket with fine supports (0.5mm thick), to reduce diffraction spikes and light loss.
In addition, this models include a 2" focuser with a 1.25" adapter, allowing the use of either eyepiece size.
Tension Control Handle
The Skywatcher Tension Control Handle provides a tension adjuster that users can easily turn to add or reduce tension, thereby increasing or decreasing the friction between the optical tube and the sideboard of the mount.
By providing such a tension adjuster, the telescope does not need to be balanced in order to stay in position.
The tension adjuster can be tightened such that the optical tube can stay in a position but can still be moved when prompted to adjust the position of the optical tube.
Alternatively, the tension adjuster can be completely tightened to lock the optical tube in position.