This black aFe POWER Filter GUARD pre-filter (part 28-10033, sold under the MagnumSHIELD name) is a slip-over sleeve that sits on the outside of a performance intake filter and catches large debris before it reaches the element. The manufacturer's own listing places it in the Filter GUARD line and ties it to a specific group of aFe filter numbers, so buyers can match it to filters they already run. Its main value is protecting an oiled Pro GUARD 7 or an oil-free Pro DRY S element from heavy grit, which helps the paired filter stay cleaner between washes than a bare filter would. It costs less than replacing a filter that has been fouled by debris.
The manufacturer lists this pre-filter for aFe filter numbers 21-90010, 24-90010 and 72-90010, plus 24-91002, 21-90021, 72-90021, 24-91026 and related numbers. The 72-90010 is a Pro GUARD 7 element that the manufacturer describes as oiled, washable and reusable for multiple cleanings, with a polyurethane top and base. The 21-90010 is a Pro DRY S element that the manufacturer describes as oil-free, with layered synthetic mesh and a conical shape. Because the sleeve matches the filter it covers, a buyer should confirm that the filter number on the box matches the list before ordering. Searches for this part typically include terms such as aFe pre-filter 28-10033, aFe Pro DRY S 21-90010 pre-filter, aFe Pro GUARD 7 72-90010 pre-filter, aFe Filter GUARD black pre-filter and aFe intake filter protection.
The manufacturer lists it for aFe filter numbers 21-90010, 24-90010, 72-90010, 24-91002, 21-90021, 72-90021 and 24-91026. Confirm that the filter number on your element is on that list before ordering.
According to the manufacturer's listing, the same pre-filter number covers both the oiled Pro GUARD 7 filter (72-90010) and the oil-free Pro DRY S filter (21-90010), so the sleeve is not limited to one filter type.
