Locks and such only keep honest people out of stuff they do not belong in. I say again honest people. If some one wants it bad enough, Fort Knox does not stand a chance.
Take that as you may but that is why we all carry insurance.
I've seen those before on ebay. Haven't used them though, so I can't say for sure how good they are.
I use a set I got from www.precoparts.com. They hold 3 trimmers and cost $69 (actually I paid $99 when I bought them 2 years ago, but now they are sold for $69).
Good racks and dummy proof because you CAN'T forget to secure the trimmer like you can on some racks.
For better pics, look at www.TrimmerTrap.com website, these are the exact same as TrimmerTraps TT-1 model (except these hold 3).