Abstract: This disclosure is directed to an improved winged catheter unit characterized by a combination of beneficial and advantageous features enabling the user to introduce intravenous (I.V.) fluids into a patient while permitting the technician to control air venting at the onset of the I.V. introduction and during change of I.V. bottles without removal of the catheter while at the same time promoting a higher confidence level of avoidance of air embolism(s). This combination also reduces the number of venipunctures necessary to secure placement and maintenance of the needle and catheter tubing. This improved winged catheter unit is characterized by a combination comprising an integral molded deck unit having centrally located therein a tapered tubular inlet portion having a larger inner diameter opening at one end through which an I.V.