ERIKS type M (type B according to the DIN standard) has a single metal casing and rubber sealing lip. Since the casing is made of metal, it must be fitted in a well-finished, undamaged groove. Large volumes of oil seals with metal casings are often cheaper, which is why they are often used as original equipment in machines. However, if an oil seal has to be replaced, types with a rubber exterior (type R or RST) are easier to fit. Type MST is similar to M and commonly used. The difference is the dust lip in the MST oil seal that prevents dust and dirt reaching the sealing lip, and extends its service life in dusty environments.

Oil seals are a crucial component in any high-pressure system, serving the important role of preventing leaks and maintaining the integrity of the system. These seals are designed to withstand the high pressures typically found in hydraulic systems, engines, compressors, and other machinery where oil leakage can cause serious damage.

The seal is usually made of high-quality materials such as rubber or synthetic compounds that can withstand high temperatures and pressures. It is designed to maintain a tight seal even under extreme conditions, such as rapid changes in temperature and pressure during engine operation.

Oil seals close off the space between stationary and moving components in the mechanical equipment. It saves the lubricant from escaping through the equipment and ensures smooth operation of the machine.