EnviroCare Replacement Micro Filtration Vacuum Bags for Hoover Windtunnel Upright Type Y 18 Pack 18 EnviroCare Replacement Micro Filtration Vacuum bags for Fits: Hoover WindTunnel Uprights Type Y and Z. Replaces Hoover Part # 4010100Y EnviroClosure sealing system to prevent dust bursts during bag removal 99.7% Micro Filtration Traps Microscopic Particles and Allergens Manufactured by EnviroCare Technologies the leader in premium aftermarket Vacuum bags and Filters