A simple fully stereo sampled Steinway & Sons model B piano in 3 velocity layers.
It is a very simple Kontakt instrument with no fancy interface and just the samples doing their thing. It is certainly not comparable to Eastwest stuff or Alicia’s Keys, but at under 200 megs it loads fully into memory and sounds reasonably good in a mix.
The Sampletank version is quite large at about 500 megs, so make sure you have plenty of free memory. I suspect it is one of the most fully sampled ST 2.5 pianos there is.
It is completely free and you are free to use it in any manner you choose.