My CR123 copper arrived today. It's quite nicely made, but doesn't seem to follow the switching sequence as described. In fact, it's quite random. A recent test showed medium, low, medium, low, medium, low, medium, high. Sometimes it stays stuck at low for a while; other times it goes low, medium, high, low etc. as it's supposed to. (Wasn't rushing, or dawdling). The main concern here, aside from the extra time needed to finally reach high, is that whatever circuit controls the cycling is marginal and might eventually fail.