The Arri M40 is the big brother of the M18 with the same Arrimax reflector, giving it up to 40% more output than a regular open face HMI. One of the advantages of this lamp is that you can use either a 4kW or a 2.5kW bulb. If you use a 2.5kW bulb, there is no need for a three-phase current and you can use regular power outlets. The ballast comes with a 5kW to 2kW adapter.

The M40 comes with a High Speed Ballast that goes up to 1000Hz.