A petition filed March 20 alleges that fiberglass door panels from China are being sold at less than fair value in the U.S. and benefiting from countervailable subsidies. The alleged average dumping margins are as high as 198.77 percent.  The products subject to this petition are fiberglass door panels (which include fiberglass sidelites) designed for permanent installation in a building. Such panels are primarily used as exterior or entry doors in residential (e.g., single-family and and mixed-use buildings but may also be used in non-residential applications such as barns, sheds, and storage buildings.  Subject goods consist of at least one fiberglass skin, frames typically made of wood or composite stiles, bottom rails and top rails, binding materials (including adhesives or fasteners), and insulation foam, and may be assembled with glass. They may be (1) impact-rated to withstand hurricane force wind loads and reinforced with steel sheet or plate and/or (2) fire-rated for up to 90 minutes and contain flame retardant composites.  The petition covers fiberglass door panels and sidelites whether or not (1) the door surface is painted, contains cut-outs for door components, or is assembled with glass lites in the door, (2) the items are imported attached to, or in conjunction with, door components and accessories (e.g., doorjambs, door handles, locks, hinges, door stoppers, door kicks, door thresholds, and trim), in a pre-hung door system, or as part of an entry door system, (3) the items are accompanied by other parts, and (4) the items are finished or unassembled.  The petition also covers fiberglass door panels and sidelites that have been processed in a third country, including by filling with insulation foam, trimming, cutting, notching, punching, drilling, painting, finishing, assembly, or any other processing that would not otherwise remove the items from the scope if performed in the country of manufacture of the in-scope product.  Imports of subject goods are classified under HTSUS 3925.20.0010 and may also be classified under HTSUS 4418.29.4000, 4418.29.8030, 4418.29.8060, or 7019.90.51.50.  The Department of Commerce and the International Trade Commission will consider this petition and launch investigations determining dumping and subsidy margins and injury to the U.S. domestic industry, respectively.