Hmmmm I cant think what you mean. Thats the only part I can see on ECat and from memory when I took mine apart doesnt it bolt straight to the subframe?
it a long bracket that runs the length of the seat at fastens on using the bolts that hold the subframe onto the seat base. its bolted upwards using the allen key studs.
the pretensoiner them bolt to the bracket which has a locating dowell on as well.