The AriesX Quark 75W Modelling Lamp is a frosted double envelope bulb designed primarily for strobes. The double envelope design is made to protect the actual lighting element of the bulb from contaminates. The frosted glass exterior provides a softer glow, distributing an even and pleasing light onto the subject. The bulb is also mercury free and does not require any special disposal. The modelling lamp has an average life of 2000 hours.