Fast switching liquid crystal compositions for use in bistable liquid crystal devices

The invention is directed to the use of a fast switching liquid crystal composition said composition comprising at least 30 weight % of a component (alpha) containing one or more compounds having a dielectric anisotropy Deltaepsilon of at least 25, whereby at least 25 weight % of said compounds have a dielectric anisotropy Deltaepsilon of at least 40; and at least 5 weight % of a component (delta) containing one or more compounds having a ratio of gamma1/TNIK of 0.51 mPa.s/K or less, a clearing point TNI of at least 100° C. and a rotational viscosity gamma1 of not more than 190 mPa.s (wherein gamma1 is the rotational viscosity at 20° C. in mPa.s and TNIK is the clearing point in degrees Kelvin); in a bistable liquid crystal device and especially in a zenithal bistable nematic liquid crystal device, a nematic liquid crystal medium, and a bistable liquid crystal device comprising said fast switching liquid crystal composition.