Scupper ValveProvides a water exit for boats with self-bailing cockpits. Acetal construction. Accommodates 3875B thru-transom thru-hull connector (screw holes must be drilled for installation.). Diameter: 2-7/8". Use as a replacement valve for 3881 Thru-Transom Scupper. Caution: Thru-Hull connectors are designed for installation above the water line only.WARNING: This product can expose you to chemicals which are known to the State of California to cause cancer, birth defects or other reproductive harm. For more information go to P65Warnings.ca.gov.