I literally just received it today. I installed the batteries and tested the system throughout the house. Two thumbs up for performance etc. It seems to work well with my Sony A7iii/Sony 90mm macro lens. I then read the manual and it suggested checking for firmware updates. I have made. I found updates on their website. I followed the rather vague instructions in the manual and now the flash heads are locked. My mistake was that I copied all the bin files onto the flash heads. You just have to copy the file with the appropriate system extension (N/C/S) behind it and then the update will work.