17.5x21x4.5 (17.25 x 20.75 x 4.38) MERV 8 Accumulair Replacement Filter for Ruud $49.84 Available FeaturesAccumulair® Filter for Ruud® Nominal Size 17 1/2" x 21" x 4 1/2" (Actual Size 17 1/4" x 20 3/4" x 4 3/8")Great for reducing air borne particles such as dust, pollen, mold spores, tobacco... Compare Add to Cart
21x24x4.5 (20.75 x 24.25 x 4.38) MERV 11 Accumulair Replacement Filter for Ruud $83.78 Available FeaturesAccumulair® Filter for Ruud® Nominal Size 17 1/2" x 21" x 4 1/2" (Actual Size 17 1/4" x 20 3/4" x 4 3/8")Great for reducing air borne particles such as dust, pollen, mold spores, tobacco... Compare Add to Cart
17.5x21x4.5 (17.25 x 20.75 x 4.38) MERV 13 Accumulair Replacement Filter for Ruud $80.86 Available FeaturesAccumulair® Filter for Ruud® Nominal Size 17 1/2" x 21" x 4 1/2" (Actual Size 17 1/4" x 20 3/4" x 4 3/8")Great for reducing air borne particles such as dust, pollen, mold spores, tobacco... Compare Add to Cart
21x21x4.5 (20.75 x 20.75 x 4.38) MERV 11 Accumulair Replacement Filter for Ruud $73.16 Available FeaturesAccumulair® Filter for Ruud® Nominal Size 17 1/2" x 21" x 4 1/2" (Actual Size 17 1/4" x 20 3/4" x 4 3/8")Great for reducing air borne particles such as dust, pollen, mold spores, tobacco... Compare Add to Cart
21x21x4.5 (20.75 x 20.75 x 4.38) Carbon Odor Block Accumulair Replacement Filter for Ruud $121.71 Available FeaturesAccumulair® Filter for Ruud® Nominal Size 17 1/2" x 21" x 4 1/2" (Actual Size 17 1/4" x 20 3/4" x 4 3/8")Great for reducing air borne particles such as dust, pollen, mold spores, tobacco... Compare Add to Cart
21x24x4.5 (20.75 x 24.25 x 4.38) MERV 8 Accumulair Replacement Filter for Ruud $59.82 Available FeaturesAccumulair® Filter for Ruud® Nominal Size 17 1/2" x 21" x 4 1/2" (Actual Size 17 1/4" x 20 3/4" x 4 3/8")Great for reducing air borne particles such as dust, pollen, mold spores, tobacco... Compare Add to Cart
21x24x4.5 (20.75 x 24.25 x 4.38) MERV 13 Accumulair Replacement Filter for Ruud $103.90 Available FeaturesAccumulair® Filter for Ruud® Nominal Size 17 1/2" x 21" x 4 1/2" (Actual Size 17 1/4" x 20 3/4" x 4 3/8")Great for reducing air borne particles such as dust, pollen, mold spores, tobacco... Compare Add to Cart
17.5x21x4.5 (17.25 x 20.75 x 4.38) MERV 11 Accumulair Replacement Filter for Ruud $66.77 Available FeaturesAccumulair® Filter for Ruud® Nominal Size 17 1/2" x 21" x 4 1/2" (Actual Size 17 1/4" x 20 3/4" x 4 3/8")Great for reducing air borne particles such as dust, pollen, mold spores, tobacco... Compare Add to Cart
21x21x4.5 (20.75 x 20.75 x 4.38) MERV 8 Accumulair Replacement Filter for Ruud $53.83 Available FeaturesAccumulair® Filter for Ruud® Nominal Size 17 1/2" x 21" x 4 1/2" (Actual Size 17 1/4" x 20 3/4" x 4 3/8")Great for reducing air borne particles such as dust, pollen, mold spores, tobacco... Compare Add to Cart
17.5x21x4.5 (17.25 x 20.75 x 4.38) Carbon Odor Block Accumulair Replacement Filter for Ruud $109.21 Available FeaturesAccumulair® Filter for Ruud® Nominal Size 17 1/2" x 21" x 4 1/2" (Actual Size 17 1/4" x 20 3/4" x 4 3/8")Great for reducing air borne particles such as dust, pollen, mold spores, tobacco... Compare Add to Cart
21x24x4.5 (20.75 x 24.25 x 4.38) Carbon Odor Block Accumulair Replacement Filter for Ruud $143.95 Available FeaturesAccumulair® Filter for Ruud® Nominal Size 17 1/2" x 21" x 4 1/2" (Actual Size 17 1/4" x 20 3/4" x 4 3/8")Great for reducing air borne particles such as dust, pollen, mold spores, tobacco... Compare Add to Cart
21x21x4.5 (20.75 x 20.75 x 4.38) MERV 13 Accumulair Replacement Filter for Ruud $89.37 Available FeaturesAccumulair® Filter for Ruud® Nominal Size 17 1/2" x 21" x 4 1/2" (Actual Size 17 1/4" x 20 3/4" x 4 3/8")Great for reducing air borne particles such as dust, pollen, mold spores, tobacco... Compare Add to Cart