The life of this battery makes it indispensable. Since I installed it in my Galaxy S2, over night or daytime unexpected extinctions of the device lifetime in normal use (WIFI and 3G internet, telephone, texting and MMS numbers, mails, various applications) over 48 hours! (12 to 14 hours max with great original battery). Anyway, I still wonder why Samsung does not sell with the original Galaxy S2. (Shame on original battery !!!). The little weight it adds to the device asks thirty minutes of adaptation, not more. The cache is the exact equivalent of the original one, and the difference is that the back of the phone ends up flat in alignment with the objective of the camera, short silicone shells and various other cases or Mofi Leather remain fully compatible. Also available with a white cover. What can I say except that I certainly would not have had to wait to buy this battery.