These are perfect for my exhaust filters. My Bissell is only 4 years old and nobody has bothered to change the exhaust filter. When I inspected the original filter, the side facing the engine was COMPLETELY black. That is, the light does not go through. I threw it away and put in a new filter, white on both sides. Exhaust flow is much better now. They cannot be washed, so I recommend replacing them every 1-2 years. Overall: 5/5 stars, value for money replacement straight fit exhaust filter.