It is lubricated and cooled by the engine lubrication and cooling systems. After cleaning, the marker should be lubricated with commercially available paintball lubricant. Dry lubricants are often used in applications such as locks or dry lubricated bearings. The drive ensures that the compressor and bearings are optimally lubricated at all compressor speeds. Corrosion and oxidation wear occurs both in lubricated and unlubricated contacts. Fluid bearings can be "hydrostatically" or "hydrodynamically" lubricated. All big end bearings are lubricated this way. The shank must be lubricated with grease to allow it to slide in the chuck. There is even very low friction, as long as the chain is sufficiently lubricated. The pivot cup should be periodically lubricated to ensure a smooth turn. Most condoms are lubricated and they allow less painful and easier penetration. The clitoral glans, like the foreskin, must be lubricated by the naturally provided sebum. Wood slides can be lubricated with paraffin wax. Many models of condoms are lubricated with solutions containing nonoxynol-9. The chain can be lubricated monthly for smooth riding.