190mm Focal Length - With compact mini-rail, suitable for astrophotography telescopes with focal lengths up to 1500mm. 
＊50mm Guide Mirror - The 50mm guide mirror has a bright wide field of view optical system that can see many potential guide stars. 1mm precision adjustment is available to help you quickly find the target in the telescope. 
＊Fast Focus - With fast focusing telescopic tube, 1mm scale, can be locked in place. Precision non-rotating microfocus, 1 / 10mm scale. With a 10mm focusing range on both sides, the spiral focuser is easy to use. 
＊Small and Compact - The very small and compact automatic guidance system adds little weight to the astrophotography equipment and can be easily fixed in an accessory box between uses. Rugged, lightweight and durable. 
＊Suitable for - Fits standard Celestron, Sky Observer, Vixen and GSO saddles. It is a good accessory for astronomy lovers.