Why do you need to use each part in the kit?

The weakest part of the door will break when it is kicked hard enough. The jamb is almost always the first part to break. If you reinforce the jamb, the lock area on the door will likely be the next part to break. If you reinforce those 2 areas, the door can easily be kicked off of the hinges. We found all of this out the hard way. If any of the pieces were not necessary, we just would not provide them. We offer different configurations because we know that different customers will want different options, based on cost or desired security level. Not everyone wants maximum security. Did this answer your questions? Thank you for your feedback