Spoon Sports 00-09 S2000 Air FilterNew version features a multilayer urethane material instead of the OEM high density paper material. The use of urethane dramatically improves filter efficiency. This filter cannot be washed and re used. Replace with normal recommended factory intervals. Upon full opening of the throttle, a huge volume of air is drawn in at high speeds. Meanwhile, when the throttle is closed, an inertial force acts and air is compressed at the instant just prior to