DP covers from Design Polymerics are plastic bags with elastic bands used to prevent dirt, dust and debris from entering ductwork during installation or during shipment. The covers are reusable and fit both round and rectangular duct. There are six sizes available and fit ductwork ranging from 6 inches round to 120 inches square.

Design Polymerics, 11609 Martens River Circle, Fountain Valley, CA 92708; (800) 641-0808; fax (714) 432-0660;www.designpoly.com.