I have a swiss tool spirit, can never remember which model, X or not, not sure it makes a difference for my question. I want to get the extension bits and I'm confused (I'm also a DIY noob so don't laugh) There seems to be available an "extension bar" and a "ratchet bar" and then the bit holder. What functions do these serve? Do I need both? And the bit holder, that takes bits that are standard size and generally available? If you could answer and keep a straight face it would be appreciated.