Hi Marco, 2. I am using 128 GB SanDisk V30 A2 Extreme functioning very well. 4. I use a SPAX (Screws) box for this, which is slightly bigger than the audiomoth. Fix the audiomoth in it tight with the mic up to the translucent part. Take a very small drill and make a hole where the mic is, prepare it on the inside with moisture resistant tape. The box has a practical hanging aid as well ;-)