This is a set of 5 - 12mm X 40mm Wheel Lug Bolts for the 1960 - 1985 Mercedes models with Steel or Aluminum Wheels.
These lug bolts are for steel or aluminum wheels NOT the light alloy "Bundt" style wheels.
These bolts are 10.9 hardened steel and measure 40mm lung with a 12mm X 1/5 thread, 109 hardness, 19mm of thread.
If you have light alloy "Bundt" style wheels you need the 52mm long bolts, however if you have a steel wheel spare tire you will need a set of 5 of these bolts for the spare.