This is an Apollo Turbopump impeller. It is about 2 feet long from end to end and weighs a lot. This is a very, very, very precise piece of equipment. Either from F1 or J-2 engines, but it is impressive, regardless. The partial paperwork that came with this explains that it is as perfectly balanced as was humanly possible back in the 1960’s. Remember, this was before CNC milling, when metal things like this had to be jigged and run by hand. Precision was really, unbelievably hard back then, and yet they made this. Actually, many of these. Impellers for pumping LOX or Kerosene or Liquid hydrogen, which was capable of spinning at 28,000 (Yes, twenty-eight THOUSAND) RPM. This is the finest example of precision engineering and milling I have ever seen.
These are some pictures of the original Redstone engine.