Krytox 1506XP (1506-XP) PFPE, sold here by the 2.2 lbs (1 Kg ~0.5 liter) containers with part number 409031, is for use in chemical processes which require inert mechanical vacuum pump oil fluids. Krytox XP oils contain a soluble additive to prevent rust. This patented additive enhances the performance of Krytox VPF fluids, giving them improved performance properties. The long-term antirust properties repel moisture, providing extra protection from corrosion of metal parts and bearing surfaces.