I previously bought a green filter* for my Hoover wind tunnel and the second time around the filter now had a hard plastic flange instead of a flexible one. (flexible to fit and seal in the hole where it fits). I ordered this Hoover product instead, even though it's about double the price (1 for $25 vs 2 for $25). The filter ended up having the correct flexible flange and fitting snugly onto the vacuum cleaner - and everyone was happy. What to avoid: *Green Label 2 PACK Type 201 HEPA filter for Hoover Windtunnel, Savvy and Empower vacuums. Replaces OEM no. 43611042, 42611049, 40140201. Durable