As previous poster mentioned, the 16GB microSDHC cards are available. I've found that the higher capacity micro cards generally (trial and error is the rule of thumb) work in most devices, especially if SDHC is listed. My 16GB card is working quite nicely in my Sirius Stiletto 2. And as ScottC said above, if it doesn't work, at worst you're only out a few bucks for the 4 and 8GB cards, and not much more for the 16GB (I paid $60).