Made in USA. This fiber screen + carbon filter fits perfectly into 6 inch diameter air ducts with an outer diameter of 5.92 inches. It will prevent small objects and particles from entering your duct system. Carbon filter layer has an estimated MERV 4 rating and will also reduce some odors. Rigid polymer frame is weather resistant. Works well with greenhouses, small shops, and other light duty filtering applications where small objects, particles, and odors are a nuisance. Easily secured at intake with duct tape or hose clamp (not included). Disclaimer: This product is not intended for use with hazardous gases. Max Temperature 180 F. Product works best in duct systems located near the fan/blower and may not allow sufficient airflow if used in conjunction with very low powered fans/blowers. Actual filter MERV rating may vary. A portion of this product is 3D printed and may show layer lines or cosmetic imperfections that will not affect product function.