Description Outerwears Pre-Filters are designed to keep out larger particles of street debris such as rubber, dirt, and sand from getting into and clogging the pleats of air filter elements. Premature clogging of an air filter will result in loss of horsepower and an increase in service intervals. Outerwears Pre-Filters are uniquely designed to protect your engine and the performance air filter investment without sacrificing airflow or horsepower. Particles as small as .005" are filtered out extending filter life. Even in harsh conditions including heavy moisture, an Outerwears Pre-filter will enhance your filter's ability to continue flowing the necessary air required for maximum performance while reducing the possibility of water ingestion into the engine This prefilter is intended to be installed over the airbox cage inside the stock airbox of the referenced dirt bike(s). The KTM Pre-Filter Outerwears 20-3198 fits the following KTM models: 2016-2019 KTM TC125 2016-2019 KTM TX125 2016-2019 KTM SX125 2016-2019 KTM SX150 2016-2019 KTM SX-F250 2016-2019 KTM XC-F250 2016-2019 KTM SX-F350 2016-2019 KTM XC-F350 2016-2019 KTM SX-F450 2016-2019 KTM XC-F450 2017-2018 KTM FE501