Melt extrusion printers generate VOCs while printing because the heating temperature of ABS, PC, PA and other materials is relatively high, resulting in more VOCs. Materials such as PLA with lower melting points produce much fewer VOCs during printing. These VOCs are absorbed by our activated carbon air filter. Function: adsorb volatile organic compounds. Service life: 1140 (60 days, cumulative printing time). Please refer to the following replacement methods: 1. Remove the plastic cover 2. Gently pull the carbon filter to remove it 3. Install new carbon filter 4. Install the plastic cover. Colour:Black Material:Paper and activated carbon Package Contents: 3 x Activated Carbon Filter Only the above package content, other products are not included. Note: Light reflection and different displays may cause the color of the item in the picture a little different from the real thing. The measurement allowed error is 1-3cm.