Assembly Step 1. Insert a HEPA filter into the center of the filter tank. Step 2. Use a funnel to add activated carbon to the outer tank. Fill until the carbon covers the highlighted holes in the tank. Step 3. Cover the filter tank with the lid. Secure with three (3) M3 x 6mm screws. Step 4. Attach the base to the 120mm fan with three (3) M3 x 6mm screws. Step 5. Snap the filter and base together. Your SUAFT 120 is now ready!