DOMO nHance LNS25s Biconvex Aspherical Pair of Lenses for Virtual Reality Google Cardboard 3D VR Headset The nHance LNS25s is a biconvex lens having 25mm diameter and 45 mm focal length. It can be used in google cardboard (VR) and are compatible upto version 1.2 of the cardboard design.