[Q] Mobile VR Headset with Best Field of View ( FOV ) ?

I want to know which Mobile VR headsets are available in the market with the biggest field of view ? I came across the two products Samsung Gear VR and Zeiss VR One that were better than Google Cardboard in design to give better FOV because of their wider lenses .

Samsung Gear VR vs Zeiss VR One , which one has bigger FOV ? If anyone has used them then give the review for these two or any other headsets .