We have seen some people install the washer that comes with the G-clamp between the clamp and the Omega bracket: this is incorrect.

To achieve maximum holding strength, the M12 washer shall be placed between the head of the bolt and the G-clamp when the G-clamp is fastened to the Omega bracket; when the G-clamp is fastened directly to a bracket, the washer shall be placed under the nut. The correct washer placement is shown below.