I've written about this before. A quick search brought this up:
"A good skewer has an internal cam enclosed by the lever-side of the skewer head. External cams have too much friction for a proper closure. Further, some (but not Hope in this case) have cams that slide against a plastic piece. This is a very poor idea since the plastic deforms long before you have the type of tension in the skewer required for a proper fix of the rear wheel. Good skewers will also have steel teeth, not aluminium. the latter does not bite into the frame enough to create a secure fit. You'll notice on good Shimano skewers that the skewer nut is mostly aluminium (for weigh) but has steel inserts with teeth.
Skewers require far more tension that most people give them."
I can also add that the internal cam is always steel on steel, not some lightweight stuff on plastic. If in doubt, buy any skewer made by shimano. The are all excellent. And....read the shimano skewer user instruction. It is online, a search will produce it. It is excellent advice.
I have a scan on my hand from closing a customer's crappy skewer to proper tension, that then broke and cut my palm.
The link produces by
@colin J shows good pictures of the two for comparison. I skim-read it but I don't think the article tells you enough about the doings and screwings of crappy skewers.
The skewer bible says:
1) Shimano or Campagnolo
2) No shyty external camps
3) No lilghtweight unobtanium metal skewers
4) If in doubt, revert to Number 1.