The 24-piece set includes 16 outlet sealers, 6 switch plates, and 2 decorative covers.
Promising review: "Socket sealer. Say it with me. Socket sealer. Alliteration can be so much fun. Okay, now with that out of our system, down to brass tacks. I love these. They're cheap and easy to install. They block the draft that is sure to come out of an electrical outlet or a light switch. I've used these in apartments and in houses. They work both ways. Just unscrew the plate, slap one of these bad boys in, and screw the plate back in. Just be sure to not touch metal to metal or skin to metal. It's a good idea to flip the breaker to deactivate the outlets you're installing these on. Otherwise, you'll give yourself a nice jolt. Or three. You know how everyone tells you not to stick a fork into an outlet? The same principle applies here except your finger is the fork and you can't taste purple for a while. So do yourself the favor of flipping the breaker before installing these. Don't make the same mistake as I did. Once. Or maybe three times. I can't remember too good now." —Frequency Jones
Get the 24-piece set from Amazon for $2.74.