A device intended to measure and regulate the flow of a medical gas [e.g., oxygen (O2), carbon dioxide (CO2), nitrous oxide (N2O), helium/oxygen gas mixture (heliox), medical air] during various procedures (e.g., therapeutic administration, anaesthesia, insufflation during surgery). It is a fixed-orifice device with an adjustable valve that controls the gas flow rate, and includes a calibrated Bourdon tube pressure gauge intended to measure pressure and display it as flow rate. It will be calibrated to a specific medical gas and have a dedicated flow rate range, therefore some types may be dedicated to a specific patient group (e.g., neonate, infant, adult) or clinical use.