Where does this go?

Found this piece of rubber sitting loose on the engine under the tank of my 03 Speed Triple. According to the fiche it looks like it sits under the tank or it's rear mount but unsure exactly where. Anyone know where this should go?

 

Thanks Wasp but it appears to have another use. No.21 in the picture and it appears separate from the mount but near it given the dashed lines.

 

I thought that initially but it does not fit along with these parts. I'm suspecting it sits somewhere under the tank probably to give it a cushion on a cross member on the frame.

 

Thanks