LightPix Labs announced a new CoGrip thumb rest for Ricoh GRIV/GRIII cameras with fully functional TTL hot shoe pass-through. You can get one from Amazon or B&H Photo (models for other cameras are also available).
Additional information:
CoGrip thumb grip with full-function TTL hot shoe pass-through
Most thumb grips force you to choose between better handling and shooting with flash. CoGrip solves that- it’s the first thumb rest designed to keep your camera handling solid while still allowing you to mount a multi-pin TTL flash or hot shoe accessory device.
Integrated the full-function multi-pin hot shoe passthrough
CoGrip is fully compatible with TTL / auto flash or other hot shoe accessory devices, e.g., wireless flash trigger. CoGrip also works with shoe-mounted optical viewfinders, LED lights, microphones, or any cold shoe accessory, giving you total freedom without compromise.
Shoe mount with spring plate inside
CoGrip features a spring-loaded hot shoe mount, with the exact structure of the camera’s original hot shoe. It provides spring tension to secure flashes and microphones, especially for cold shoe accessories.
Scratch-proof silicone pad
The nonslip silicone pad on the back of the CoGrip improves stability and protects your camera from scratches during mounting.
Aluminum alloy solid structure
The thumb rest part is precision-crafted from anodized aluminum alloy with a premium finish. CoGrip combines lightweight strength with long-lasting durability.