I'm experimenting with different sized and shaped steel cages right now, buying the cheaper models from Amazon. Generally, they all come with a barrel type lock, and I'm wondering what the long term durability on these things is? I've got one I've been wearing daily (but not overnight, so removing and relocking every 24h) for some months now, and it's tarnished from the original bronze they tend to come in, but seems to be working fine. It may be my imagination, but it feels like it's getting a bit gummy - and I wondered what the failure rate on them is? I know they're in use on many plastic devices too - anyone had one in for a while, or had problems with them? Do they fail?