A collection of non-sterile devices intended to be integrated within a breathing circuit to enable interface of gases between the breathing circuit and a respiratory monitoring device for sampling the patient's expired gas for measurements of pressure, flow and/or gas analysis [e.g., end-tidal carbon dioxide (EtCO2) concentration]. It includes both a tube/mask breathing circuit connector with sampling ports (sometimes referred to as a spirometry sensor) and gas-sampling/monitoring respiratory tubing; no electronic devices are included. This is a single-use device.