A suitable seal is available for any application with rotary shafts. For standard situations, oil seals are mainly used. In hard-to-reach applications, the rotary shaft seal is usually made from rubber-reinforced fabric. This simplifies mounting. For special applications, a PTFE lip seal can be a good solution. A PTFE lip seal is often used for applications where high-pressure or temperature play a role, or when friction must remain low. Are you just trying to keep it out dirt or water? Then use a v-ring or an alpha seal or connect the end of the shaft with an end cap.