Promate Camleash-Duo Easy Dual Shoulder and Body Strap for Compact...

Dual Quick-Strap Camera Sling for Compact and DSLR cameras
Camleash-Duo is worn around the shoulders and is adjustable to fit most photographers.
It can carry 2 cameras or lenses vertically at the side. The locking system connects the straps to the tripod socket located on either the camera body or the lens.
Once connected, the cameras hang upside down, resting securely at the side.
The wide strap with generous neoprene shoulder pad is extremely comfortable even with heavy cameras and the smooth slider is easy to use and adjust.