These sachets contain citronella oil, lemon eucalyptus essence, mixed herbal extracts and NO HARMFUL CHEMICALS.The sachets themselves, are made of woven polyester which help make the bags so effective – they don’t absorb moisture, are hypo-allergenic and do not promote the growth of bacteria.100% Safe to use throughout your house – linens, mattresses, pillows, couches, carpets, curtains.Expels dust mites, who are smaller than a grain of sand, without harsh chemicals. Prevents new dust mite eggs from hatching and kills the ones that are already living in your home.Clears allergens for respiratory health, improving breathing and reducing, if not eliminating, asthma attacks.Improves SLEEP and overall wellbeing – no more congestion, snoring, headaches and waking up groggy and unrested!Comes in Pairs - optimal for placing one under each corner of your furniture and rugs!