Classic German hausschuhe (house shoes) or slippers. The company that made these for us was founded in 1942 and this is their original pattern of house shoe. The cut, the sole and the pattern are the same as they were in 1942. The only differences are the glue used on the sole and the general fabric content which now has more synthetic fibers. The soles are made of a sort of dense foam rubber material, which is actually correct for the era.
These were made without the modern tags and labels to make them closer to what they would have been in 1942 and they were able to find the original size ink stamps their grandfather used to mark the soles rather than a modern tag (unfortunately the size 46 does not have this stamp as that one wasn't present). The size 46 also has a black inside fabric whereas the others have a tan color. The company appreciated that we took an interest in their history and they had some fun embracing their origins to produce these. The newer materials will make these rather more durable.
Sizes are listed as EU sizes and as US men's shoe sizes. These do run a little on the small side. If you are between sizes, it is recommended that you size up. According to the maker, it is good to size up, because the fabric sole rim is broad compared to models by other manufacturers. Slippers are non-returnable if worn.
You do not understand Germans unless you understand house shoes, particularly in a more historical or traditional context. When you enter a house, you take off your shoes and put on slippers. While these are called house shoes, one could just as easily call them Tornisterschuhe as I have seen numerous original pictures of German soldiers wearing their house shoes around the Kaserne and even closer to the front. This style of slipper does date back well into the 1800's, according to my collection of original catalogs, but I think most Germans today would have no idea they go back that far. Truly a timeless classic.