I didn't take a top view photo but I did check the serial numbers to see if they were all in the same series. I wrote down the first 6 characters of the serial number 116MLH... Somewhere online I found a chart which provides a key to this code and I think from these numbers the manufacture date translates to 11 June 2011. Edit: attached chart 96603_Module_Identification by David White posted Feb 29, 2016 at 1:17 PM