Using your K&N Universal Rubber Air Filter is easy. First, find the right filter for your equipment based on the air intake's angle and diameter. If the size is a bit off, you can stretch the rubber flange up to 1/16 of an inch (1.5mm) to make it fit. Install the filter securely on your equipment. When using it as a replacement for the OEM air filter, keep in mind that you might need to adjust the jetting. As for maintenance, since it's washable and reusable, clean it regularly to keep it performing well. You can follow the cleaning instructions on the product packaging. Also, always check the attachment to make sure it's secure and there are no signs of excessive wear on the rubber flange.