Product review (3 stars): ... I received only had 4 vanes but it works fine. The pump is slightly noisier than the original ...
The impeller on the failed pump had 10 vanes as does the pictured one but the one I received only had 4 vanes but it works fine.  The pump is slightly noisier than the original but once again it works well in our 10 year old Bosch dish washer.