The Uber rare MG3 rubber buffer pad for tank or tripod mounting. We finally have a small number back in stock after being sold out for 7 years.
For many shooters the best way to fire your MG42 is from a tripod. When mounted on a Lafetta or double gun mount, it is best to remove the buttstock so it does not rattle loose or crack while being fired.
The Germans use this rubber pad over the back of the buffer to protect the shooter from bumping into the rough end of the gun. Furthermore this protects the buffer while the buttstock is removed.