Mosquito Repellent Coils

Does anyone know where the Repellent Coils are sold? Thanks in advance. Also, if you know of any other repellents that are effective, I would sincerely appreciate your input.

Comercial had them. They didn't do much to prevent mosquito bites when we were staying on the water near Playa La Madera a few years ago, especially when using floor and/or ceiling fans during the night. They probably work best in sealed rooms - but then if the bugs don't get ya, the fumes from the coils will.