This rigid chimney liner system is designed to increase the efficiency of an existing chimney and avoid the expense of making minor repairs. For existing chimneys that do not have the correct flue size for the heating appliance, a properly sized rigid liner can correct that problem, the company says. According to the manufacturer, the chimney liner has a unique snap connection pipe for quick and easy installation; no clamps or screws are required. Designed for use in natural gas-, LP gas-, oil-, and wood-burning appliances, the chimney liner is made of high-grade stainless steel and comes in 5-, 6-, 7-, and 8-in. diameters. It can be used in older and new chimneys. Z-Flex Inc., 20 Commerce Park North, Bedford, NH 03110; 800-654-5600; 603-669-0309 (fax); firstname.lastname@example.org (e-mail); www.z-flex.com (website).