These angled risers affect the turning radius of your longboard by changing the rotation angle of the trucks. These risers have a 6 degree angle, but you can download and edit the included Blender file to fine tune the exact angle that you would like.

By positioning the higher edges toward the middle of the board your board becomes more sensitive to your shifting weight and can execute sharper turns.

For other ideas on how to use angled risers, check out this page: http://wiki.silverfishlongboarding.com/index.php/Truck_Information#Risers

I printed mine with a shell thickness of 1.6mm, a fill density of 50, and layer height of 0.1mm.