The No. 66 Auto-Vents are float-operated vents for use on convector radiators, baseboard radiation and radiant panels. These are designed to be used in space that is limited and can be installed in trouble spots previously neglected or improperly vented. No air chamber is required. The No. 66 Auto-Vents are designed for systems with pressures up to 50 lbs. No. 66 and 67 Auto-Vents can be used with the No. 9AS Shortstop Automatic Shut-off. For safe waste use the No. 7A Connector.