FILTERWEARS Pre-Filter K252K For K&N Air Filter RC-3680, RC-3680DK Breathable mesh cover wraps around your air filter for additional protection. Deflects dirt and harmful road debris that would otherwise clog or damage your air filter. Hydrophobic technology repels water in wet and rainy conditions (water repellent). Used to maximize performance and extend air filter life. Straps at the base of the pre-filter for easy do-it-yourself installation.