2 X BMW vent screws / bleed screws.

As used to bleed the cooling system.

Check compatibility section to see if it fits your car.

BEFORE YOU BUY - CHECK THE SIZES AND MAKE SURE IT IS THIS EXACT PART YOU REQUIRE - DONT JUST BUY IT - CHECK FIRST AND ALSO MAKE SURE YOUR OLD ONES LOOK EXACTLY THE SAME AS THE ONES PICTURED. 

Sizes:

Head Diameter : 16.5mm

Total Length Top To Bottom : 17.5mm