Combustion air vent for heat producing appliances. Internal baffles reduce light and draughts. Verifiable equivalent area calculation by Advantica. HETAS approved for use with solid fuel appliances. Core drilled - suitable for retrofit installations. Cowl/grilles U.V. stabilised to protect against fading. Tube: 127mm Dia. x 358mm L Cowl: 217mm L x 210mm H x 93mm