The radiator of the F 800 GS is only screwed to the frame at only one place; all other attachments consist of slot-in rubber bushings. A fall or extreme loads when riding off-road can cause the plastic loop to tear off - which can spell the end of the ride!
This strong Hard Part, made of 3 mm stainless steel, is a replacement for this angle bracket, and provides additional support for the radiator on the filler neck. This means the radiator is securely attached, and is effectively protected against sliding out of the rubber bushings.
The original screws are re-used in assembly.