I am very attached to my Win 8.1-Phone, so I was rather unfortunate that the old (black) back cover began to creak more and more lately. Well, unfortunately I had to drop it on several occasions, resulting in a total not mind it, but where it bounced every so unfortunate that the battery cover jumped. My fault. The happier I was when it dawned on me that you can replace the battery cover. And in all colors, even my favorite color yellow. Ordered, delivered immediately - unpacked, fits perfectly and bombproof. All buttons can be operated as before. And at a very reasonable price! Once again I come to the conclusion that the Nokia Lumia series much power for (relatively) has little money - a versatile, slick device that looks with the help of this cheap battery cover always different and always surprising !! The only restriction: The yellow back cover is smoother than the black, which I had previously - therefore it will be easier for me now out of his hands. So on my fine motor skills I should work urgently yet. Nevertheless, a great value for money. My Lumia 520 is now a real eye-catcher! :-)