If you have a telescope that comes with a Vixen/CG-5 style dovetail bar, or just with tube rings and no dovetail bar, and your mount can accommodate the wide CGE-style bar (e.g. CGE, CGE Pro, CGX, CGX-L, CGEM or CGEM-DX mount) then Celestron’s CGE Universal Mounting Plate could be for you. This wide bar is more rigid than the thin CG-5/Vixen size bars so is ideal for carrying heavier loads or where you want to reduce the possibility of flexure.
Apart from attaching a telescope with tube rings, you could attach a guide scope, a ball head socket and a cameras too. Furthermore, using two dovetail clamps at either end, you could dual-mount two small telescopes for astroimaging for example.
This 355mm/14″ long mounting plate has a wide elongated hole and is drilled with several of the most common hole types and patterns, including 3/8”-16, 5/16”-18, and 1/4”-20 which is ideal for attaching different and a wide range of accessories. You can find more about the hole pattern of this bar here.