I do it even a little shorter:
+ The Silicone Case / bag can be great on the Mp3 player pull over
+ Key functions can be recognized even with the envelope
+ Casing does not impair the functionality of the MP3 player buttons
Is +/- the price, let's say, not outstanding and would be for me no reason to buy
- Processing (punched for Mini-SD card slot, display, volume control, headphone jack and USB slot) could be better
I would still make the purchase again ...
Regards