Meade LX200-ACF 10-Inch (f/10) 145K object Database Advanced Coma-Free Telescope with Autostar II Hand Controller f/10 Advanced Coma-Free Optics: Building from a classic RC design, Meade has created a new design with the same coma-free pinpoint star images and flatter field also reduces the astigmatism and eliminates diffractions spikes found in classical RCs Meade Ultra-High Transmission Coatings (UHTC) increases total light transmission and image brightness by nearly 20% over Meade's standard coatings. Objects such as stars, galaxies and nebulae will appear significantly brighter Zero Image-Shift Microfocuser allows you to obtain precise image focus with no image movement Oversize Primary Mirror diameters are greater than their listed aperture. This additional 1/4" yields a wide, fully illuminated field-of-view Primary Mirror Lock locks the mirror in place preventing movement during long-exposure astrophotography