The Hamsource 817/BKT mounting bracket was specifically engineered for the FT-817 series.
It can support the radio from above or below.
It therefore can be used in a base or mobile environment.
This item consists of:
Radio Mounting Plate
Rectangular base Plate
Triangular Base Plate
Allen Screws 
Sheet Metal Screws 
Reminder: Do not put your radio or mounting bracket in a position that will interfere with the deployment of air bags or personal restraint devices.
This is not a Yaesu product.