A completely new innovative design using a new seal housing with a modern high temperature seal insert. New type seals can be replaced without stripping the engine replaces the original seal a new low friction type.
This is a significant advantage but may not be necessary as the new type seal material is much more durable than the original Sachs type. It is a simple matter to prise out the old seal and replace with a new one. Many have been installed since their introduction 3 years ago and no failures have been reported. Price is for 2 (one matching pair).