This is a Dutch East Indies Undated Pre Stamp Wrapper.  It was sent from Soerabaya to Rotterdam with a receiver mark on the back.  It was sent via TRIESTE. 

The thing to note about this cover is that it has a small Oval SOERABAYA Handstamp in BLUE on the front, 347c.  There is another smaller red SOERABAYA circle on the front as well, but this one is not well shown.

Take care because this item, though in very good shape, is still extremely old!