WILLIAM OPTICS REDCAT 51-III WIFD f/4.9 REFRACTOR BF25 with a central RMS radius

with a central RMS radius of only 3 microns

On the telescope side you can find an M48 female thread with 2" barrel while on the camera side is an M54 male thread

tracking or pointing objects

The Double telescope option is compatible with all the plates used on the GM3000 series

5 5mm T2 extension + T2 spacer 1mm + T2  spacer 0

WILLIAM OPTICS REDCAT 51-III WIFD f/4.9 REFRACTOR BF25 with a central RMS radiusThe William Optics RedCat 51 III WIFD brings the new internal focusing mechanism to one of the most popular telescopes ever. This makes it simple to install autofocusers such as the ZWO EAF without the need for clumsy belt driven add ons. The RedCat 51 III features the same excellent Petzval optics as its predecessor, but the addition of the WIFD focusing mechanism makes the whole package more stable, precise and far easier to use. Unlike the previous