Material - Body & Flanges : SUS304, Mechanical Polishing & Electro-polishing - Vacuum Side O-ring : Viton Black - Cylinder side O-ring : NBR - Actuator : AL6061, Anodized - Bellows : SUS316L, SUS316 Ti, etc. Required Air Pressure : 4 ~ 6 bar Differential Pressure : <1.2 bar Max working Temp : <60℃ He Gas Leak Rate : <5.0 x 10-9 STD cc/se