they are really good. I've been using them for months now, and I don't see bed bugs anymore. Even tho cockroaches and ants are much less now. their website chinchex.sg is very informative and you can purchase from w w w.amazon.sg/Chinchex-Bed-bugs-Insecticide/dp/B082TVPHPG/ref=sr_1_1?keywords=chinchex&qid=1579660063&s=gate way&sr=8-1
i love the fact that they are no harm to human and animals. their tutorial videos are useful too, I follow their steps and DIY myself.