K&N Custom air filter 56-1350 fits the following carburettors:

Weber DCOE 40,42
 

Product Specifications
Air Filter Height    1.75 in (44 mm)
Air Filter Inside Diameter    6.125 in (156 mm)
Air Filter Shape    Oval
Inlet Diameter    1.625 in (41 mm)
Mounting Hardware Included    Yes
Neck Flange    1.625 in (41 mm)
Overall Height    2 in (51 mm)
Style    Oval
Top Material    Chrome

Weight    1.3 lb (0.6 kg)
Product Box Height    6.75 in (171 mm)
Product Box Length    7.38 in (187 mm)
Product Box Width    6.38 in (162 mm)

Replacement Filter E-3321