Single layer of medical grade hepa filter material will clean air particles down to 4 microns. 10 microns = one human hair.Coolshirt recommends to change the filter after every race weekend.Instructions:1. Place screen with prongs facing up over blue fan that is inside of the motor housing.2. Center one single layer of filter material over screen3. Slide the 3” clear hose BLUE connector over screen and motor inlet housing and secure with clamp or tie wrap. DO NOT OVER TIGHTEN CLAMP.Sizes:Filter and Screen set: 3″
