Looking for some rear disks. The 1KU are considerably cheaper. What the difference?

1KZ are 310mm diameter and ventilated

 

1KU are 300mm diameter and solid

 

Bore Ø [mm]15,3

Brake Disc Thickness [mm]22

Brake Disc TypeVented

Centering Diameter [mm]65

Diameter [mm]310

Height [mm]48,5

Hole Arrangement / Number09/10

Inner Diameter [mm]169

Minimum Thickness [mm]20

No. of holes 29

Number of Holes5

Pitch Circle Ø [mm]112

Weight [kg]6,8

Fitting PositionRear

Fitted Quantity2

PR Number1KZ

 

 

Brake Disc TypeSolid

Diameter [mm]300

Height48.3mm

Hole Arrangement/Number5

Thickness12mm

Fitting PositionRear

Fitted Quantity2

PR Number1KU