When you purchase your defender(s), just purchase one of these clips for whichever defender you want it to be placed on. If you order more than one defender then you have to tell us exactly which defender(s) you want your clips to be placed on. For example, if you order just a defender 1 and a clip for it; that is a no-brainer. However, if you order 4 defenders and want just two of them to have clips, order two clips and then tell us which defenders you want the clips to be placed on. You can email us from the website or directly to email@example.com. Clips are $6.95 each which includes installation on the defender of your choice.