Dovetail adaptor. In order to use our new style flash brackets, the lens plate must have a double-dovetail. The double-dovetail design allows a clamp to be mounted on the bottom of the plate (as when your lens plate clamped onto your ballhead) or on the top of the plate (to accomodate our new clamping flash brackets).
The FB-A accessory retrofits your existing lens plates to use our B-series Flash Brackets. Mount the FB-A on all lens plates from Really Right Stuff or Kirk that do not already incorporate a double-dovetail (all Wimberley lens plates already have the double-dovetail design). Simply install using the special screws that are provided, and then use this new dovetail for mounting our new flash arms.
Note about clearance: The FB-A raises the clamping surface for the flash arms by 2/10ths of an inch. There must be, at minimum, 5/8-inch of clearance from the surface of the plate to the barrel of the lens.