I am a customer of glade plugins and was excited to find them at a great deal on amazon. They are easy to use, but of course you need to have the glade plugin first in order to use the oil refills. I really like the smell of the Fresh Mountain Morning and Clear Springs. It smells fresh and refreshing. These are good to use in places like the bathroom, laundry room, and living room. This is where I use them. This is a really great deal on these and I would highly recommend buying them!