Aluminum Range Hood Filter with Light Lens - 11-3/8" X 11-3/4" X 3/8" Features approx 2-1/2" Light Lens on long side of filter Attributes: Contains an aluminum foil pad between two pieces of expanded aluminum with a light diffusing lens. Usage: This washable aluminum filter with a built-in light diffuser is used in ducted and ductless range hoods. Maintenance: We recommend that the filter be washed as often as required to prevent grease build up and a resultant decrease in air flow. Soak in a solution of hot water and degreaser for 10-20 minutes. Agitate gently to remove loosened grease. A residue of grease on the filter after washing is acceptable as this helps retain grease.