87 HONDA CR250: UNI Multi-Stage Competition Air Filter Uni Multi-Stage Competition Air Filters are unsurpassed in airflow, dirt stopping and overall performance. And they produce more horsepower and more torque than any other air filter. Uni's revolutionary two stage air filter is the only filter that comes apart for maximum airflow and ultimate cleaning.Traps dirt and dust in 2 layers of foam.The large pore, pre-filter captures the bigger particles.The small pore, inner filter preven