Confused about the resolution for IOS 6+ devices

I had designed one app for IPhone 5 and 6 and now I want to make the same app design for IPhone 6+ so what can be the resolution of its assets?

Currently I had done following things in Photoshop.

• 
  

  IPhone 5 or less: Icon Size= 55X55 (x)

  
  


• 
  

  IPhone 6: Icon Size= 110X110 (2x)

  
  


• 
  

  IPhone 6+: Icon Size= 165X165 (3x)

  
  

Still I am facing problem is slicing. Is is correct resolution? or what is the correct way to slice for IOS 6+ Devices?

Thanks.