Why use cases which are so heavy while Apple is trying to reduce the weight of the iPhone! 
Now try this screen protector that is light but protective! 

Designed 9H Tempered Glass Screen Protector 

Features:

9H Surface Hardness
2.5 D Curve at edges
Full coverage of your iPhone 

Models Available: 

iPhone 5/5s

Other models like 6/6s Plus or 6/6s, please proceed to my shop page.

Customers can expect to receive the items 7 days after order confirmation.