Choose the cable that works with your Celestron telescope. The CGX-L fits the large Celestron CGE-style dovetail and the smaller CG-5-style dovetail, also common to the using Celestron CGX mount with PHD2 - posted in Beginning Deep Sky Imaging: Hey All , Ive been using a CGX mount for the last year ; but now Im going to add a guide scope into the system . All these cables are generic and can be purchased from any supplier. Product description The Celestron CGX-L GoTo EQ Mount improves on the venerable CGX platform to provide users with a heavy-duty research-quality mount for larger optical tube assemblies (OTAs), accessories, and imaging rigs. I do not have a view of Polaris from my home ; and so , I use Celestrons all star polar alignment routine . Celestron's engineering team applied their years of experience designing German Equatorial mounts to the all-new CGX EQ, a culmination of all the advancements made to our technologies, value, and ease-of-use. For CGX and CGX-L mounts… PC equipped with USB 2.0 or 3.0 Type A ports (only for cable connection), and one of the three cables listed below. INSTRUCTION MANUAL Model #91531 EQUATORIAL MOUNT AND TRIPOD. There was a recent thread on using the PECTool with cgx-L - and my main point about it with all celestron mounts including this one is that you may need to guide through the st4 port while you do the training. In this day and age I really don't think anyone needs to resort to manual guide corrections … The CGX was designed to better support your telescope for both visual and astro-imaging pursuits.