HQRP 6-Pack Secondary Filters for Hoover Self-Propelled U6471900 U6476900 U6476910 U6485100 U6485200B U6485300B Upright Vacuums Coaster HQRP&reg; 6-pack Windtunnel Secondary Filters Replacement + HQRP&reg; Coaster; This filter are located behind the grill in the bottom of bag compartment, protects the motor from dirt particles; Replaces Hoover Secondary Filter part # 38765-019, 38765-023; Measures 5" x 2 3/16" x 3/8" with a rectangle notch; 100% Compatible with Original filter. 2 weeks DOA replacement warranty!