25mm Biconvex Ultra Clear Lens includes the following features : 

• Ideal used for Google cardboard
• 5 Times of magnification
• Focal length: 45 mm
• Thickness of the center point: 4.95 mm
• A convex lens facing the phone, the flat side toward the eye, the image will not be reversed

Material :

• Acrylic

Size closed :

• Diameter of 25 mm
• Weight of 2.5 grams