Mininert® Valves are unique PTFE vial closures featuring inertness and syringe access without exposure of the vial contents. These push-button valves are highly dependable, leak-tight closures for screw-cap vials and other laboratory containers. When used with a glass vial, only PTFE and glass are in contact with the sample. Mininert Valves are ideal closures for calibration standards, air or moisture sensitive fluids, derivatizing reagents or volatile chemicals. They are easily installed without tools. The screw-cap Mininert simply threads onto the vial. The crimp-top version slides into the neck of the vial and features a threaded flange which can be turned to secure a tight fit. Mininert valves afford easy access to the contents via syringe. A silicone rubber gasket above the PTFE valve stem (isolated from the contents) provides a seal for the needle when the valve is open. It prevents leakage or exposure of the contents during sampling. Push the green button to open, insert the needle and take sample, withdraw the needle, then push the red button to close. To change the needle-seal septum, just push out the old septum and insert a new one with the valve closed to avoid exposing contents. Mininert Valves can be used up to 105°C.