b9m8
2006 F Sprinter, 2007 D Sprinter
I bought an aftermarket engine block heater from Amazon but I'm having a hard time finding where it goes. The red arrow is blocked by some metal stub (looks like hex, but its fairly rounded form factory) and there are two blue plastic plugs (freeze plugs), but which one do i use?
Any help is appreciated, thank you so much!

Any help is appreciated, thank you so much!
