Minolta Lightmeter IV and IVf

[iceberg]

I was looking for 2nd hand ambient light meter and I came across the
Flash Meter IV and Auto Meter IVf. I read through the manual for both, and it seems that both are equally capable of similar functions e.g. Spot metering attachment, flash metering, ambient and incident light metering. Anyone who's familiar with both of them, care to share the difference between the two?

thnx
Berg