The medium steel discs are included as standard with the Diamant D.525 and are great for pretty much all bakes. 85% of flour falls through a 0.3mm sieve.
As such, this is not item is not an accessory, but a replacement part.
Fine Steel Disc pair
The fine steel discs produce very fine flour that is suitable for even the most delicate bakes such as cakes. 90% of flour falls through a 0.3mm sieve.
Coarse Steel Disk pair
The coarse steel discs are not designed to not create flour, but to simply crack the grains / crush the grains open. This is ideal for things such as fermenting such as making your own beer using crushed malt. ‘Bruised Grain’ is also a term used for this type of cracked grain when it comes to producing easy to digest cattle feed.