First you have to check which Planar you have.
If it's a C series Planar you should look for B50 lens hoods, if it's a chrome one you should look for the metal shade, if you have the black one you should look for the plastic one. They're compatible anyway but it's more philologically correct to chose the one that were meant to be used for a certain series.
If you have a CF series Planar you have to look for the B60 lens hood.
First you have to check which Planar you have.
If it's a C series Planar you should look for B50 lens hoods, if it's a chrome one you should look for the metal shade, if you have the black one you should look for the plastic one. They're compatible anyway but it's more philologically correct to chose the one that were meant to be used for a certain series.
If you have a CF series Planar you have to look for the B60 lens hood.