For some time a discernible trend in the use of cassette seals for extremely dirty environments has become apparent. The multitude of designs for the many applications makes, however, their comparison difficult. Results from one application (e.g. pinion) cannot be carried over to another (e.g. hub). Consequently, a sealing system suitable for axles subject to very dirty environments, such as off-road vehicles, was developed. With relatively minor modifications, it could be used for most of the important applications such as pinion, hub and propeller shafts in general.