The APO Barlow from TS combines good image quality with compact design. So this lens cannot only be used with Newtonians, but also with refractors and diagonal mirrors without touching the mirror surface.
The three element design improves field correction and prevents from introducing chromatic aberration, retaining the image quality of your telescope.
A brass compression ring locks accessories gently and with precision.
The large clear aperture allows the use of eyepieces with longe focal length without vignetting.
The TSShorty-Barlow lens is designed in such a way that the Barlow element (i.e. the focal length extending optics) can be unscrewed from the holder.