The aFe MagnumSHIELD Pre-Filter (28-10013) is a black, slip-on dry-weave polyester sleeve that fits over the outside of a paired aFe intake filter. It catches larger debris before the air reaches the filter media. The manufacturer lists a 6-inch base, a 4-3/4-inch top, and a 9-inch height, and the fabric is designed to repel water and dirt with minimal effect on airflow. Because the sleeve takes the abuse, your performance filter stays cleaner for longer, which stretches cleaning intervals and cuts the frequency of replacing an expensive filter. It is a practical upgrade over running a bare filter on a dusty trail, track day, or dirt road. Searches for aFe Magnum Shield pre-filter black, aFe 72-35035 pre-filter wrap, and dry weave polyester air filter pre-filter usually lead to this exact part.
Each pre-filter is made for a specific aFe filter, so the fit depends on the filter it goes over. The manufacturer's listing names the 21-35035, 24-35035, and 72-35035 filters, along with the matching -40035 series, and also lists a few other aFe part numbers, including 21-30028, 24-30028, and 24-45509. Check the filter number before ordering. The pre-filter is designed to be cleaned with soap and water, which is simpler than replacing a filter. Installation is a slip-on job that needs no drilling or cutting. Use the pull tabs to seat it over the filter and make sure it sits evenly before reinstalling the filter in the airbox. The manufacturer also states that this pre-filter does not require a CARB Executive Order number, which is worth knowing if you care about emissions compliance.
The manufacturer lists compatibility with the 21-40035, 24-40035, 72-40035, 21-35035, 24-35035, and 72-35035 filters, along with 21-30028, 24-30028, and 24-45509. Confirm your filter's part number against that list before ordering.
No. The manufacturer states that this product does not require a CARB EO number.
The manufacturer says it can be cleaned with soap and water, so it can be reused rather than replaced after each dusty outing.
This is a beginner-friendly, no-tools-required job. The pre-filter slips over the aFe filter using its pull tabs, so there is no drilling, cutting, or modification to the airbox. Remove the filter from the airbox, slide the pre-filter on, and reinstall the assembly. Before you start, match the pre-filter to your filter's part number, since each pre-filter is made for a specific filter. Seat it evenly so the fabric does not bunch up at the top or bottom, which keeps the seal and airflow consistent.
