I bought this product when my child was 9 months old (when he started pulling up to stand).By 10 months he could pull the plugs out of the wall...and he is not even walking yet.
(I could not get a refund because I no longer had the receipt.) They said it's just supposed to be a deterrent..well duh! I guess it is supposed to be used for babies who can't even crawl, because crawling babies can defeat it.
Please do not think of purchasing this product if you wish to keep your child safe from electrical sockets.