274# and 275# silicone fluid for super high vacuum diffusion pump are colorless, transparent oily fluid and own very low saturated vapor pressure , good heat resistivity property,. excellent resistance to high temperature, oxidant and radiate. Used in high vac., electronics Industry, coating for high vac., particle accelerator, electronic microscope and display, etc. Similar as Dow Corning704 and 705 Diffusion Pump Fluid.