This part is a direct replacement part for the HPI E10 drift car used to increase ride height by about 5-7 mm. i recommend using an 80% infill. in my particular case i am converting my drifter into a touring car hence constantly dragging on the ground was being an issue hence i decided to add some ride height and it was the easiest way. it just takes 2 screws to remove the factory part and this will fit directly in it's place. this can be used on both front and back suspension.