Pay attention! I had tried 3-4 professional pest control companies in a ground floor apartment, with a severe cockroach problem in the drains. I didn't dare leave any hole open, and in August I would even find small ones that of course came out from the closed caps. No professional solved my problem permanently like this particular product! I put the small size inside the bathroom drain, which just barely fit (I removed the grate, etc.) and turned it on. It killed everything and as a precaution I put another one after two months. Nothing ever appeared again. The smoke penetrated all the pipes. I don't know if this is the approved method for a closed drain and certainly in most cases the smoke bomb doesn't fit inside, but I solved my problem after years!

It was used in a cesspit. It is excellent for reducing mosquitoes. But afterwards, you also need a larvicide for the eggs. It is excellent

I have a septic tank completely sealed off behind my ground floor apartment and somehow it connects to my pipes, you can understand that if I leave anything open, hundreds of cockroaches will invade! The only thing that worked for me is this particular product. I put the 15g inside the shower drain, which could also fit in terms of size (I have a large drain, in most cases not even the small one fits) and it really killed everything! I covered the hole with a cap and the smoke did its job. Not even the professionals I've been bringing in for so many years have done such a good job. I don't know if it was right to put it in a drain with limited space, but I got the job done!

I put it in the septic tank and nothing was left
very good as it has no flame.
it definitely needs to be repeated after two months though, as whatever it kills, the eggs will remain

Very easy to use, with no dangerous flames. It seems to have done its job well. It was used in a shed in the countryside. It killed-stunned even small scorpions.