This ultra-thin case are made of high quality Plastic compatible with iPhone 6/6s/7/7plus 4.7-5.5 inch perfectly remains the slim profile. 
Full Protection: The back shell with two elcetroplated sections and the screen protector guard your phone against shocks or scratches in a seamless style.
The ring can be turned 360 degrees which provides you with multiple viewing angles for handle-free for watching videos and movies.
The ring is made of aluminum alloy and built in the shell,stable and versatile, it allows you to have a better and safer grip on reaching more parts of screen by sliding your finger right through the hole.
The case made of PC material will not block the signal and it can always keep the signal full grid.