{"product_id":"dayton-20ua21-louver-damper-adjustable-18-h-x-18-w","title":"Dayton 20UA21 - Louver Damper,Adjustable,18 H x 18 W","description":"\u003cp\u003e21 In.H 21 In.W Drnbl Extrd Alu Combo Dmpr, Louver Type Combination, Frame Type Flanged, Outside Height 17 1\/2 in, Outside Width 17 1\/2 in, Rough Opening Height 18 in, Rough Opening Width 18 in, Louver Maximum Intake 779 cfm, Maximum Exhaust 1,114 cfm, Flange Width 1 1\/2 in, Free Area 0.7 sq ft, Beginning Point of Water Penetration 1,118 fpm, Maximum Air Velocity 3,000 fpm, Blade Angle 45 Degrees , Material Aluminum, Inside Height 16 1\/2 in, Inside Width 15 3\/4 in, Number of Blades 3\u003c\/p\u003e","brand":"DAYTON","offers":[{"title":"Default Title","offer_id":43255201300574,"sku":"20UA21","price":564.61,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0663\/7151\/8558\/files\/Z-oJytocpEx_4c879bff-bca3-4d94-9109-97100f127a25.jpg?v=1788402226","url":"https:\/\/nationalboilersupply.com\/products\/dayton-20ua21-louver-damper-adjustable-18-h-x-18-w","provider":"National Boiler Supply","version":"1.0","type":"link"}