the previous (identical) cartridge did not last very long and it would have been useful to be able to visually check easily that the contents were close to empty, but this is not possible without ripping it apart.
Comment from Prink:
These cartridges contain more ink than the genuine Borther equivelent and are filled to maximum capacity. There is a clear window in the cartridges so you can physically check to see if there is any ink remaining.
This item is also compatible for use with the printers/products below