I am relatively new to chastity cages and am currently locked into a CB6000, though a Jail Bird from Mature Metal will soon be on its way.
At the moment the keys to the cage itself are always with the Keyholder, though once I switch to the Jail Bird, we will be locking the keys to the Jail Bird in a portable security box which will stay with me, and she will keep the keys to the security box. Owing to our work, she will be moving to Hong Kong in late January and I will be able to join her not before a year. I learnt of chastity cages only in the last few months. She trusts me, but for whatever reason, I thought doing this might give her piece of mind or more likely (since she likely will have that without the cage anyway) a symbolic expression of love and commitment on my part (as corny as it might sound, crazy ideas we men get, eh).
She had reacted indifferently to the idea initially, though she seems to have warmed to the idea somewhat (she even had the courage to deny me once already unless I pleased her first

Anyway, here's me introduction. I'm sure I will learn a lot from you over time.
Happily caged.