I've gone in a different direction with my suspension so these are no longer needed. The front struts are already installed into factory type housings, one less thing you need to do to get them on your car. They have 12 or so track days and only a few street miles on them and are as new.
You will notice one extra strut insert in the picture below. When I received the struts, one arrived DOA, the charge was gone and some oil had leaked out. Koni quickly sent me a replacement so the DOA insert can be used for extra parts.