I have the SGS2 with "gepimptem" battery (Samsung EB-K1A2EBEGSTD battery case back for Galaxy S II), that my phone is slightly thicker than the original shape. Nevertheless, it fits in just fine. The mobile phone is inserted through a slot at the top of the back (this is the jack for headphones accessible). The material is enough to order the SGS2 good push in and out, but is tight enough to keep the phone well. The display can be operated by the film. To my arm (muscular female arm) adjusts the belt without difficulty, with heavily muscled men arms it is probably a little short. Materials and workmanship I like that, in materials, Passform- or Nähmängel could previously recognize. And the bag is also an unbeatable price! Conclusion: strong buy recommendation, if you're not Markenfetischist!