Review on Enhanced Colorfullife Filters for Shark Vacuum Navigator Lift-Away ZU503AMZ, NV350, NV351, NV352, NV355, NV356E, NV357, NV360, NV370, NV391, UV440, UV490, UV500, UV540, UV541, UV550, Part XFF350 XHF350 by Aries Greene

I'm assuming that either most of these reviews are fake or the positive reviewers don't realize the importance of a good fit for these filters. Any open gaps will make the motor susceptible to dust buildup, which will drastically reduce your shark's suction power. This shortens the life of the vacuum cleaner, which ends up costing you more just for trying to save a few bucks. There are other, higher quality, third party vendors that sell the same filters except they fit and have absolutely no gaps. Avoid this brand or be prepared to replace your vacuum cleaner.