The Volkswagen Beetle, Transporter and Porsche 356 pre A used the Bosch RED 130/6/2600 AL16 alternator which uses a Volkswagen protection ring without any holes in them.
Diameter is 90mm.
Porsche also used an later style protection ring for the Porsche 356A/B.
Part number mentioned in PET is “616 109 381 00”
Diameter is 90mm.
