Molykote High Vacuum Grease is a stiff, non melting silicone lubricating material and has much higher stability at the higher end of the temperature range(-40 C to 200 C), than hydrocarbon greases such as A pie zon M, However, its initial room temperature pump down characteristics are not as quite as good taking noticeably longer to out-gas. This grease is very popular as a general laboratory lubricant, in large part to its low cost relative to the alternatives. The product is very popular as a stop cock grease as well as for use as an anti-seize grease in ground glass joints. It is the recommended replacement for Molykote Stop Cock Grease. Molykote High Vacuum Grease is also used to lubricate synthetic and silicone rubber gaskets being used in high temperature applications. It should not be considered for use on fluoro silicone "O" rings and gaskets. Molykote High Vacuum Grease is recommended for vacuums reaching between 1x10-5 and 1x10-6 tor.