The ornamental design for a case for mobilephones, as shown and described.
1. Case for mobile phones
1.1 : Perspective
1.2 : Front
1.3 : Back
1.4 : Left
1.5 : Right
1.6 : Top
1.7 : Bottom
1.8 : Perspective view 2
1.9 : Reference view
The broken lines depict portions of the case for mobile phones that form no part of the claimed design; reproduction 1.1 is a front perspective view of the case for mobile phones; reproduction 1.2 is a front view thereof; reproduction 1.3 is a back view thereof; reproduction 1.4 is a left view thereof; reproduction 1.5 is a right view thereof; reproduction 1.6 is a top view thereof; reproduction 1.7 is a bottom view thereof; reproduction 1.8 is a back perspective view thereof; reproduction 1.9 is a reference view showing the design in use wherein the broken lines within the opening form no part of the claimed design.