The innovative 'GLOWdim' feature of this low voltage LED MR16 spotlight light bulb allows the spotlight to change colour temperature as it is dimmed, going from a warm white light at full brightness to extra warm white at its lowest setting.At full brightness, the light bulb emits a sharp 345 lumens of warm 2700K light, warming to 2000K when it is dimmed. It is compatible with most standard dimmer switches (please see the manufacturer's website for more details), and its GU4 base retrofits to existing light fixtures, meaning installing the light bulb is simply a case of swapping out the old one for the new.The lamp's focused 36 beam angle makes it a versatile option that is suited to everything from task lighting in the home, to retail and display lighting.Please note, as this is a low voltage light bulb (12V), it needs to be fitted with a compatible low voltage driver/transformer when installed on a mains circuit. GLOWdim tuneable white technology - 2700K warm white - 2000K extra warm