According to Giesemann’s website:

MEGACHROMEcrystal – the perfect light source for all marine aquariums that need a strong light performance in combination with a high blue / violett ratio.

The MEGACHROMEcrystal metal halide bulb offers excellent coloration and high intensity. It is crystal / crisp-white with a light violett / blue tint. It brings out the fluorescent pigments in corals nicely. Fluorescent supplementation is usually not necessary, but can be used for added intensity and to simulate dawn and dusk.

The light spectrum has a pink accent and shows fluorescent effects on many corals which gives a completely different impression of the colour.

The very high colour temperature of this bulb is achieved through a special manufacturing process which at the same time guarantees a long colour stability which is a problem with many bulbs towards the blue end of the spectrum.

This bulb contributes to a healthy growth of your corals and produces stunning colours in your reef aquarium. An excellent choice for reef tanks with SPS and LPS corals.

colour temperature: over 17.500 Kelvin
available in 150 and 250 Watt double ended