ciao,i purchase a pair of 4343b,in good condictions where is the difference between 4343 and 4343b,but the medium have a dustcup nout of the centre,i look a type with dustcup in centre.sorry for my bad english.
i speak in italian.
il mio modello ha la cupola del medio rivolta verso l'esterno,io ho visto altri modelli con la cupola verso l'interno qual'e la differenza.
sorry.
the difference in photo of medium.