I have yet to meet any child safety feature designed to protect a child; defeat a child. Not even one child.
By 15 months they're able to pull the plug covers out which is just at the stage you need them the most. They're able to open the cabinets. I don't care if it's the ones you open the cabinets slightly then push down on or the ones with the straps you have to push buttons on all three sides to open the door. The refrigerator door locks, the toilet safety locks. Even child safety caps on a medicine bottle. When you can't get one off, hand it to a 2 year old they'll be able to get it off in a heartbeat. Forget window safety locks burglars may not be able to get past them, but I'll guarantee you, you'll have brought 5 set by the time the child is 3.
If you find one that does as it actually claims let me know and we'll nominate it for the only actual child safety device that works. What we had to do by the time our oldest granddaughter was two and have had to keep up was buy the cheap .97 cent chain locks you can buy at Wal-Mart or Home Depot any home goods type store and put those at the very top of the door one for every door including the bathrooms. 2 cheap screws for the windows, that in case of a fire we can open just enough to lift up and out, but that they can't open enough to climb out.
Edit to add: This is also what we did for our own children and their safety. 20 bucks you're done till they're in school. Advised by our own parents and how they protected us. For our grandchildren we thought spending $100's of dollars was the way to go. Pfft.
Edited on 10/23/2009 at 9:06:23 AM PST