TEMPERED STEEL BRUSH - Stiff steel bristles clean coal and soot from masonry flues, and chimneys GALVANIZED STEEL STEM - Heavy duty double-spiral stem for long-lasting durability 1/4 INCH NPSM FITTINGS - Features 1/4" male pipe threads for use with our fiberglass rod kits (sold separately) PROFESSIONAL QUALITY - Superior components provide excellent performance MADE IN USA - Quality manufactured in the Midwest! Midwest Hearth 6-Inch Square Wire Chimney Brush with 1/4-NPSM fittings.