I sharing my experience with you that I am using the good knight low smoke coils and it is a very bad product because it is a not a low smoke coil, it produced the dense smoke and it have a bad smell. It is not killed the mosquito completely.
When it kept in the room, it have dense smoke completely occupied the room and very difficult to breathe.
It caused some many respiratory diseases like asthma and pneumonia. It have the prallethrin chemical causes the diseases. And it not user friendly.
Overall, it is a very bad product.
