The vintage VW dash mileage counter has a magnetic base and the size is about 4x3cm.

It is an accessory that you can use to note the mileage of the next fuel fill up or oil change.

After the tank is filled with fuel, you just roll the wheels on the counter to match with the speedometer mileage and you are on the way. You then compare your mileage to it and you know how far you have driven. After about 350 kilometer with your VW bug, it will remind you to fill fuel up again. It is a must have in a vintage car without a fuel gauge. No more notes...

You can call it vintage dash mileage counter or:
vintage mileage counter
KM kilometer counter
mileage counter
mileage minder
kilometre minder
oil change reminder
small mileage counter
manual dash remind counter
dash trip counter
fuel reminder
trip counter
manual odometer
trip odometer
fuel odometer
KM Boy
gas boys
gasboy

The first picture shows the Vintage dash mileage counter in an German Autozubehoer Katalog Halt from 1965.

Below you see lots of variations of the miles counter sold in in German between 1953-1970.

Vintage mileage counter fuel VW T1
VW T1 Bus with vintage mileage counter
Vintage mileage counter fuel
kilometer, oil change and departure reminder in white and new old stock
KILOMERK
KILOMERK
Tankfix Oelwechsel oil change reminder
Tankfix Oelwechsel oil change reminder
Tankfix
Tankfix
Tankfix mileage counter VW Gute Fahrt 07-1963
Tankfix
Tankfix Abfahrt KM Miles Gauge for VW Split Oval Beetle
Tankfix Abfahrt KM Miles Gauge for VW Split Oval Beetle
Tankfix Abfahrt KM Miles Gauge for VW Split Oval Beetle
Tankfix Abfahrt KM Miles Gauge for VW Split Oval Beetle
Tankfix Abfahrt KM Miles Gauge for VW Split Oval Beetle
Tankfix Abfahrt KM Miles Gauge for VW Split Oval Beetle
KILOMETER-BOY
KILOMETER-BOY
white, ivory aged Kilometer Boy
white, ivory aged Kilometer Boy
Mileage Fuel KM remind counter 1968
KILOMERK
Vintage kilometer counter black VW T1
VW T1 Bus with black KM counter
kilometer, oil change and departure reminder in black and new old stock
VW T1 Bus with black mileage counter
Dash fuel gas remind counter
TANKEN
ABFAHRT, TANKEN
Kilometer Boy abfahrt tanken 1964
TANKEN, ABFAHRT, OEL
vintage Tankfix KM Counter 1961
Tankfix
KILOMETER
An old point of sale display. The cool display is made of metal, so the store owner could put new magnetic miles counters easily.
Oellux oil change reminder VW Oval
This is the rare Oellux. The Oellux is made of metal and a very early mechanic oil change reminder. It can be mounted on the VW Oval bug steering column.
Oellux
VW Oval Bug 1953 with Oellux fully loaded - WOW
Oellux thumbwheels, the good old quality
Oellux in Kraftfahrzeug Zubehoer 1957
Oellux in Kraftfahrzeug Zubehoer 1957
DBGM Chrome Kilometer Counter in my 1959 VW bug
DBGM Chrome Kilometer Counter in my 1959 VW bug
DBGM Chrome Kilometer Counter
DBGM Chrome Kilometer Counter
Chrome Kilometer Counter in 1965 VW bug
Chrome Kilometer Counter in my 1965 VW bug. The first owner put it in...
Made in Germany kilometer dash trip counter in black / silver with a sticker on the rear side.
VW T1 Bus dashboard with a made in Germany kilometer trip counter in black / silver.
Made in Germany kilometer dash trip counter in black with a sticker on the rear side.
VW T1 Bus dashboard with a made in Germany kilometer trip counter in black.
magnetic KM dash trip counter
VW T1 Bus dashboard with magnetic KM counter.
magnetic KM-Merker in parts catalog
VW T1 Bus with magnetic km dash trip counter
magnetic KM MILES dash counter
Volkswagen T1 Bus dashboard with magnetic KM MILES counter.
MEKO miles recorder with instruction
MEKO miles recorder with instruction
MEKO kilometer recorder with instruction
MEKO kilometer recorder with instruction
new old stock MEKO miles km counter
new old stock MEKO miles km counter
Meko made in East Germany (DDR) KM counter
Meko made in East Germany (DDR) KM counter
Vintage KM MILES counter with matching photo frame
Vintage KM MILES counter with matching photo frame
km-miles Thermo in parts catalog