The largest sandisk I could find in a regular CF was 128 gb. The adapter has a master and a slave slot. Tony said it would be wise to use one card instead of 2. I have high quality mp3(bit rate of at least 320 or flacs, I may try and use some WAVs. All which use a lot of hard drive memory, but use less song names to use less file indexing. I figured buying a 256 gb card, which seems to be hard to find unless its a type B Compact Flash, which has larger dimensions. I think I found a lexor that is 256 gb though. I am still looking. If you know of any please let me know.