Please read carefully - CCA stands for Copper Clad Aluminum and there is no governing body that can certify the performance/specification of cables rated 5e/6/6e etc. This means that any "guarantees" and "specifications" that vendors make may be fictitious as there is no governing body overseeing these specification claims. I have worked with an OEM to develop a cable that will work at CAT6 level in some environments (which may be unethical) to fool myself or other customers which is why I'm giving it two stars instead of one. If you're cutting cables yourself in an easily accessible and detachable configuration, CCA cables are likely to do just fine - if cables exhibit undesirable characteristics, simply replace them. However, if you plan to route cables through closed/inaccessible areas, it makes sense to omit CCA cables entirely. Since the return period has expired I will be buying pure copper cable again (and paying a silly tax in the process) but this is a warning to future buyers.