The K&N Phenomenon...                                                              
The World's Best RC Filter System. K&N developed and manufactures the only air filtration system of its kind…a high-flow, washable filter that’s been proven, again and again, to protect today's expensive RC engine! Its innovative design and a unique oil suspension system make K&N air filters, without a doubt, the very best for your engine. MILLION MILE WARRANTY, you buy it once, clean it and reuse it again and again.