This is the one single brake disc. If you plan to change discs on the entire axle then you should buy two products.
Dimensions and size
|Brake Disc Thickness||17||mm|
|for article number||09.9728.14|
|Number of Holes||4|
|Supplementary Article/Info 2||with screws|
|Brake Disc Type||Internally Vented|
|Tightening Torque||85 Nm|