Santovac 5 Polyphenyl Ether is a vacuum diffusion pump fluid which operates efficiently, economically and safely to produce ultra-high vacuums of 4 x 10^-10 torr, and higher, at 25°C. Diffusion pumps are the most economical and reliable means of reaching these low pressures and Santovac 5 has proven to be the best pump fluid available for this type of equipment. Due to this fluid's extremely low vapor pressure, backstreaming characteristics are lower than any other fluid resulting in less contamination and longer operation. Santovac 5 is ideal for use in many applications including laboratory, analytical and research operation, vacuum production, thin films, space simulation chambers, and optical coatings. Santovac 5 is a very pure fluid and as a result vacuum chambers and components remain cleaner, therefore, this results in less system maintenance and downtime. Also available in 500 ml bottles.