Spectra flange

You may get from the online site “pupsik” and search for “maymom” brand which is compatible to use for Spectra pump.

Spectra do not have a 20mm flange, would need to get from third party manufacturers like maymom

I got maymom flange from shopee instead they have smaller size and suitable for spectra too.

Kiddy palace or mothercare

Maymom flange from Qoo10

got mine from lazada

Shoppee has too

Pupsik or qoo10

Kiddy palace

Online store