Confused about PME prisms on 2000 series Hasselblads

I'm looking at the specs for the PME45, for example, and it says it's compatible with the 203FE and 205FCC.

Why would you ever use a metered prism on those cameras when they have their own built-in meters? I'm confused.

I know the PME45 has spot metering, which the 203FE doesn't have...so is that it?

THanks,

Mark

The compatibility will only entail having the cut-out in the prism's base front edge that allows room for the display in 200-series cameras. Not all prisms do, and those that don't must not be mounted on 220-series cameras, or they will damage the display.

You could use a PME45 on the 200-series cameras, yes. But you're right that there is no really good reason to do so.