Thank you for viewing. This is an introduction to the Märklin genuine part 757010 / E757010 hex nut. This part is difficult to obtain, so I imported it personally. It is mainly the nut that connects the main rods (connecting rods) of Märklin analog HO gauge steam locomotives. (See the arrow in the photo) It's a troublesome part that you might notice is missing during operation. I believe it can be used on most Märklin analog steam locomotives, but please check the exploded diagrams, etc., of your own vehicles to make your final decision regarding compatibility. However, I can also check if you leave a comment, so feel free to ask. NCNR (No Claims, No Returns) please. *The vehicles and rails in the photos are not included in the product.