The locking feature must be new - mine doesn't have it and i've lost one key and nearly lost a small Swiss Army knife. I won't use it for anything critical now and am hesitant to spend $10 to buy a second one. Neat idea, solidly made and with the locking feature should work well.
great for keeping keys organized especially if you have to take them off, no more trying to open the key ring. The only thing is the one main clip on the top has a tendancy to unclip if you have a key ring cliped in there.