The conventional energy saving bulbs were designed for inside use & normal room temperatures. Müller Licht cold resistant energy saving bulbs have been especially designed for use outside & for rooms with low temperatures like garages, cellars & cool rooms. The bulbs are cold resistant up to – 20° C & even shine brightly at low temperatures. * Amalgam / cold resistant up to -20° C * Specially designed for outside use * Shines brightly, not dependant on temperature * Average life 10, 000 hours * Start up quickly * Light colour 2700 K, warm white Not dimmable! Average 10, 000 switching cycles 15 W is the same as &8805;54 W light equivalence 20 W is the same as &8805; 77 W light equivalence