Civacon's family of Vapor Adaptors offers the highest-flowing, lowest-backpressure vapor-recovery connections available. Models are available that feature an optional bubble sight glass that clearly indicates to the operator if any condensed liquid vapor has collected inside the adaptor or vapor-recovery header. The 1711T Vapor Dust Cap fits all models of 4" Vapor Adaptors and provides a vapor tight seal as well as preventing any environmental contaminants from entering the vapor-recovery system.