These are the La Marzocco portafilters people on coffeegeek have been raving about, with the 15 degree angled rubber handle. It will fit all E61 group machines as far as size goes.
The one problem when using it in an E61 group machine (Andreja Premium, Anita, Vetrano, Isomac, Giotto, Grimac, Euro 2000, or Expobar) is that it doesn't lock into place properly. It will only turn slightly to the right. For that reason, we recommend you also purchase a thinner group gasket than what comes stock with the E61. Stock is 8.5 mm; we recommend 8 mm, this will give you a tighter fit. This is important for safety reasons; if your portafilter is only slightly locked into place, there's a chance of it popping out as pressure builds. You run the risk of getting burnt.
Insert baskets are not included. This portafilter does not fit a Silvia without some filling, and therefore I do not recommend it nor will I accept returns if purchased for use in a Silvia!