Hollow board, strictly speaking, there are two kinds of materials are PP with PE, PE now with not a lot, mainly roof insulation, the market generally are PP material, hollow board has a lot of names, grid plate, Wantong board, corrugated board, PP board, a variety of shaped packaging, honeycomb, S-type, not lattice-type specifications. Uses a lot of electronics, hardware, packaging, advertising, boxes, many companies are used, the market potential is great, but the competition is very, very low profit margins, was innovative.