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Wearing a camera neck strap cause the camera to pivot upwards which can be uncomfortable, especially with a long lens. This device feeds the two straps to a base plate which shifts the pivot point. The camera and lens will now lie flat and not bounce around so much. 
The original strap and camera tie points are retained so in the unlikely event that the plate breaks the camera will still be protected. Originally designed for an OM-1 but easily modified to suit your camera. Base plate is held in position using a captive tripod screw.