[]NIKKAKU LABORATORY official shop]Ninja ROBO Refills Standard size 3 pieces -House dust mite trapping tool his product is Ninja ROBO 3 Refill mats!! Mite extermination 100%Mite breeding control comparison test Aiken Corporation (Testing Institute, Japan) findingsMade in Japan!! Attracts mites easily!!Place it anywhere to get rid of Dust Mites.One is sold every 30 seconds in Japan. Here is an effective setting placement!! Bed, Sofa, baby bed, closet, carpet, toy box etc Effect of Ninja ROBO 3 months from date of opening package. Refills are more economical and environmentally friendly! Dust Mites contribute to more than 80% in allergy related diseases such as asthma,rhinitis and eczema. According to the World Health Organization, it is estimated that approximately 300 million pepole suffer from asthma worldwide and even more are affected by allergic rhinitis.