The 'Perfect Range' of Fittings comprises of Swagelok type, Parker type and Ermato type tube fittings.
The swagelock type twin Ferrule tube fittings are your best bet for high pressure vacuum and vibration applications and made of stainless steel material.These fittings are absolutely leak proof plus a torque free seal at tubing connections can help you say good bye to expensive hazardous leaks in instrumentation and process tubing.

Parker type and ermato type single ferrule tube fittings are good for low and medium pressure, vacuum and vibration applications.Ermato type fittings are made of mild steel and stainless steel.