MANN Aircleaner used on industrial engines.
Part is mentioned in the manual for the Beetle until 1952 and the Barndoor parts manual untill 1954.
This MANN fuel filter is commonly seen on Porsche 356 Pre A engines.
Tuners like Denzel and Okrasa also used these on there engines.
Numbers as seen on the lid are: BF329 & KD 08.49