Consisting of three layers of metal net. Absolutely safe for people to touch the outer nets with barefinger or body, but not safe to squeeze the nets. Zapping bugs dead instead of squashing. Convenient to kill mosquitos or bugs effectively, quickly and clean in the house or outdoors, no smell, no chemical, and no environmental pollution. The net meshes are too small to enable children's fingers to get through while mosquitos or flies can do with its whole body.It will initiate static force around the net zone when switchedon, and there for, whenever the small bugs get in touch with the outer net, they will be attracted to the inner net to be zapped and killed.Normally, bugs will possibly be zapped into pieces in one ortwo shocks.