This is brand-new (1 month ago). I bought it to prevent my toddlers from spraying the hose in the house all the time ; )
It replaces your normal water spigot handle. You unscrew the handle from the shaft, then screw this on instead. It spins freely until you put in the magnetic key, at which point you can actually turn the water faucet on and off.
Unfortunately, the existing spigot that we have is an unusual oval shape, as opposed to the more typical circle or square type that this is designed for. So, sadly, I wasn't able to use it. Instead, I purchased their FaucetLock, which is cheaper, and works well, but involves actually detaching and attaching the hose every time you use it. The Guard n' Lock doesn't require you to remove the hose -- it just goes right on the existing shaft. I wish I could use it, but I can't, so I'm listing it here, unused, for about $10 off sticker price.
Here's a link to the official website description: