Fuel filter - Mann723 or Mann731

[Mataji]

Can anyone tell me the difference between these 2 filters? The pre-filter fitted to my Nanni 3 cylinder engine is a Mann WK723. I have seen a recommendation that it should be a Mann731. A service is now needed and I don’t know which filter to buy.

 

[Stemar]

Dimensions for both:
731 H=117mm

723 H=124mm

The only difference is the length, and you have the longer one. I'd say that they're interchangeable, at least for your application.