Vented Loop Vented loops are anti-siphon safety devices for use with both manual and electric marine toilets installed below the waterline (static or heeled) Warning [https://productimageserver.com/prop65/6pt.png]WARNING: This product can expose you to chemicals including LEAD which is known to the State of California to cause cancer, birth defects or other reproductive harm. For more information go to P65Warnings.ca.gov [http://P65Warnings.ca.gov].