Smells a bit like sweaty feet but I was impressed by how well it worked for our new cat.
18 month old Harry Cat had been very skittish for a few days before I bought this plug-in, and I must confess, I was a little skeptical. However, after a few hours of plugging it in Harry went from running and hiding behind the sofa as soon as you moved or stood up etc to a cat that was laying on his back with legs akimbo and not a care in the world.
It really helped him settle into his new home.