Our largest aperture SpaceProbe reflector telescope is the niftiest Newtonian reflector on an equatorial mount we've seen in a long time. The Orion SpaceProbe 130ST EQ Reflector Telescope is a step up from the standard SpaceProbe 130 EQ for the more serious beginning or intermediate stargazer who wants additional performance, particularly for targeting deep-sky objects. Just what's so nifty about the Orion SpaceProbe 130ST Equatorial Reflector Telescope? The answer is best described as short and sweet. First, the short. This ST, or Short Tube, version of the SpaceProbe 130 reflector is indeed more compact than the standard model. The 130ST reflector telescope's optical tube measures 24 inches long compared to 33 inches on the standard 130. The focal length of the ST's 130mm (5.1inch) primary mirror is 650mm (f/5), yielding a wider field of view and brighter images for a given telescope eyepiece focal length. That brings us to sweet. The 130mm aperture primary is a diffraction-limited parabolic mirror, the same type used on much larger reflector telescopes costing many times as much. On a short-focal-length design like this one, a parabolic mirror is a must for focusing incoming light to a point and delivering sharp, detailed images. Moreover, the secondary mirror is held in an advanced holder with thin 0.5mm metal vanes, to reduce diffraction spikes and light loss. These features combined with the included 25mm (26 x power) and 10mm (65 x power) Sirius Plossl telescope eyepieces and quick-release 6 x 30 achromatic finder scope make this one sweet optical system for astronomy! The SpaceProbe 130ST EQ reflector telescope also includes a collimation cap and center-marked primary mirror for easy optical alignment. The Orion SpaceProbe 130ST telescope comes on a sturdy and precise EQ-2 equatorial mount with dual setting circles and slow-motion hand controls.