The P2S printer uses an internal circulating air handling system by default, relying on an internal activated carbon filter for air filtration. The external exhaust fan kit provides a solution for users with exhaust requirements. This kit integrates seamlessly with the printer. After installation, the printer automatically switches operating modes based on the type of consumables used. With the kit installed, the P2S have an automatic air purification function after printing. The P2S printer uses an internal circulating air handling system by default, relying on an internal activated carbon filter for air filtration. The external exhaust fan kit provides a solution for users with exhaust requirements. This kit integrates seamlessly with the printer. After installation, the printer automatically switches operating modes based on the type of consumables used. Users can also manually set the operating mode on the printer screen/in Studio/ Handy. With the kit installed, the P2S have an automatic air purification function after printing. For engineering materials requiring sealed printing (such as ABS, PA, etc.), enabling "Purify Air at End of Printing" in the printer screen settings w buffer must be purchased to use this kit. Color: As Shown Material: PC+Plastic Package Contents: 1* External exhaust fan kit(Without back panel) 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.