Lambro 10 in. Wall Cap with Damper is designed for use with 3-1/4" x 10" ducts and features a built-in damper to help control airflow efficiently. Made from durable plastic, this wall cap is available in two color options to suit your needs: brown and white. Its practical design ensures easy installation and reliable performance, making it an i choice for ventilation systems requiring a 10-inch size. Model Number: 117B / 117W