Standard incandescent GLS style light bulb with ES-E27 Edison screw (27mm) fitting for general purpose use.NB The old larger size (60mm) is now specified due to rough service lighting potentially supplied but on occasions some stock is of the new size at 50 or older 55mm diameter. Also known as an A55 light bulb with a classic opal/satin look.Please call us for clarification if required. NB - A suitable alternative of this light bulb could be supplied as a rough service version.Please note that even though the light bulb itself is IP65 rated, it must be used in a suitable IP65 rated socket in order for it to be used outside safely.Need more help in choosing a suitable light bulb? Read our guide What is a GLS Light Bulb.