WSI Test Pads Rebuilding Instructions The below video is the instructions for rebuilding the JF-WSI filter cartridges. If you have any questions please refer to our contact page and send us a message. The JF-WSI Product Page: https://www.d-2.com/wsi_astm_8073/The ASTM Test Method 8073: https://www.astm.org/d8073-22.html