Dow Corning High Vacuum Grease is a stiff, nonmelting 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 ApiezonŽ M, However, its initial room temperature pumpdown 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 Dow Corning Stop Cock Grease. Dow Corning High Vacuum Grease is also used to lubricate synthetic and silicone rubber gaskets being used in high temperature applications. However, we would urge caution, to the extent that it not be considered at all for use on fluorosilicone "O" rings and gaskets.