The only other manufacturer who uses the E-Series mist nozzle (under license I believe) is the Saudi manufacturer SFFECO who has a range almost identical in construction to Firebug's that include the 3 & 6 litre mist extinguishers.
I've had a client who has safely and effectively used a water mist extinguisher on a live 415v industrial laundry machine fire (after CO2 was ineffective) so it's not all bluff, they are as good as they claim!