Material: Polyester mesh cloth and steel wire Size: Its designed with a big size that wont fetter the insect, opening is 40*60CM . The mesh holes is about 1/50"even tiny insects can't penetrate it to get inside Function: Come with an instructions, its convenient for you to watch the growth of insects closely Mesh design: Mesh on 5 sides promotes healthy air flow, especially fine and neat mesh can avoid tiny ants, wasps and other predator insects flying into it Special design: A transparent surface allows you to see the insect's activities clearer. With this butterfly mesh, kids can observe the behaviour of caterpillar's eating and growing clearly and gain more natural knowledge.