1. With standard thread, easy to replace the ordinary breathing cap; 2. Micron filter cloths ensure no solid contamination. 3. When the absorbent is full of water, the color changes from dark red to light red, making it easy to see if it needs to be replaced. 4. Activated carbon absorbs oil mist from the system. 5. The case is made of high-strength plastic and can withstand temperatures up to 90 degrees. 6. For closed systems only;