I want you to know that the filter disc is too big for my Wind Tunnel 3 Pro Pet. I cut off about an inch and a half from the blue rubber ring, taped it together with black sports tape and now it fits. THIS WORKS BECAUSE YOU CAN SEE THE DOG HAIR ON THE FILTER. Next time I will order a REAL Hoover filter. I just don't want you to be misled into thinking it matches this brand of vacuum. The Hepa filter fits.