The V Series Side by Side System 11-Inch Connecting Bar by ADM:

ADM Dual Side by Side Mounting System for Vixen Style Mounts: The ADM Dual Side by Side Mounting System allows you to place two telescopes side by side on your Vixen-style mount. Works great with the Celestron CG-5 mount, the Meade LXD55/75 mount, and Vixen mounts! 

The ADM Dual Side by Side Mounting System allows 10-inches of separation between scopes and includes a spring loaded clamping mechanism. Spring loaded clamping mechanism. 11-inch connecting bar. OPT Product Number: AA-VSBS