The manufacturer of this product, Smart Membranes, does not assign part numbers. The specifications for this product are as follows:
Interpore distance: 12 µm
Pore diameter: 5 - 6 µm
Pore length: 350, 500 µm
Pore arrangement: Square
Please see this link to the manufacturer Smart Membrane:http://www.smartmembranes.de/en/products/macroporous-silicon/