In reply to Mr-Cowdrey:
I have a full set of Zero G wires as Cotswold were selling them cheaply. They are fine in terms of chock shape. Bit "old-fashioned", none of the sexy shaping of a WallNut or Stopper or Metolius nut etc.
However after about 12 months, one is showing some wear - a single strand of wire has "pinged", which obviously weakens it by an amount unknown until destructive testing. So I'm retiring that one.
I have much older nuts from a variety of manufacturer, all of which have seen more action than the Zero Gs IMHO, and they are fine.
It might be that the nut in question was unfortunate enough to have the wires run over a particularly sharp edge or something. Thought it worth a mention. They have nonetheless justified the purchase (think I paid about £37 for 11!), still got 9 good 'uns.
They are the exact same nuts that Decathlon used to sell as Kong Nuts. And funnily enough I have a Kong nut (much older, in fairness, maybe had it for 5 years) which also has a "pinged" wire. Again, it has already proved its worth and I don't really mean to scaremonger or slate the (UIAA rated of course) manufacture.