Blue Google Cardboard @ 45mm Focal Length Virtual Reality Google Cardboard with Printed Instructions and Easy to Follow Numbered Tabs (WITH NFC and FREE HEAD-STRAP) Instructions and Easy to Follow Numbered Tabs (WITH NFC) (Box Color) Easy to assemble. With Printed Instructions and easy to follow numbered tabs Biconvex lenses 25mm in diameter and Focal length 45mm (exact google cardboard specification) High Quality GOOGLE Cardboard manufactured by Trusted Toronto All Rights Reserved.