This is a Dutch East Indies Undated Pre Stamp Cover.  It was sent from Samarang to Rembang and written in Chinese. 

The thing to note about this cover is that it has a SMALL OVAL SAMARANG FRANCO in BLUE BLACK, # 269b!  It also has an M/S '15' on it as a postal charge!

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