Valve stem seal pliers are a tool designed specifically to remove valve stem seals. Different types are available. Valve stem seal pliers with longer stems are able to fit into the narrow valve spring cavities on multivalve engines. Serrated tips provide a good grip, which is especially important with stubborn seals. Variable-angle valve stem seal pliers are also available for use where access is awkward and made more difficult by the presence of manifolds, wires, tubes and linkages. These variable-angle models have a rotating jaw assembly which allows the pliers to be used straight or at angle up to some maximum, which may be as much as 90 degrees. The jaw tip may have a thin ledge for hooking underneath stubborn valve stem seals.