>>76397009 (OP)They are fine, for the back of the neck i recommend holding the weights in a towel and biting it, this also trains your jaw muscles.
It can be awkward to train the front of the neck with this, it's easier to put weights on your forehead, over a towel obviously, and do neck curls.
Neck harness are fine but there are better alternatives for free, if anything you can alternate using a neck harnes and bitting the towel for the back of the neck but that's it, then again you can also do neck extension putting the weights on the back of the neck like with neck curls.
Basically it's meh.