Clear Plastic Regal Thermostat Cover - Ring & Solid Bases - 6-3/8" x 3-1/2" Width_20in Actual Filter Size – 27

Actual Filter Size – 27 3/4"w x 15 3/4" x 1"

+ Product Details Size – 16"w X 20"h is the size for the duct opening measurement only

+ Product Details Size – 20"w X 50"h is the size for the duct opening measurement only

+ Product Details Size – 16"w X 25"h is the size for the duct opening measurement only

+ Product Details Size – 6"w X 10"h is the size for the duct opening measurement only

Clear Plastic Regal Thermostat Cover - Ring & Solid Bases - 6-3/8" x 3-1/2" Width_20in Actual Filter Size – 27+ Product Details Durable Construction Made with clear, high impact plastic to provide reliable and long lasting protection for your thermostat. Two Mounting Base Options Includes both a solid base and a ring base. The ring base allows installation without removing the thermostat, offering maximum flexibility. Locking Security System Features a built in eight tumbler lock and a supplied key to prevent tampering and maintain consistent temperature