Mistakenly referred to as a "Ruen". I believe (based on a
schematic inside the phone) a more proper name for this phone is "Type
51".
The confusion stems from the logo stamped
into the bottom of the instrument:
On first inspection the background
letters spell "RUEN", but if you look closely you can see the
lines defining the shortened "I" sitting on top of the short leg
of the "J". Thus "RIJEN"
which is the city where these Ericsson phones were manufactured.