I would also be interested in knowing the vendor.  In mid-March of this year, my lab-tested A1c was 5.3. My average BGs for the three preceding months had been 102 (Feb), 94 (Jan), and 99 (Dec), for an average of 98. [5.3 translates into an average BG of 111.4, which I think is high, but I understand that the A1c can give a skewed average for a number of reasons, among them having red blood cells that live longer than the average 90 days.]

My average BGs for March, April, and May were all 100. I would have expected, given the slight two-point rise from the prior 3-month period, an A1c in early June that was only slightly higher than it had been in March (maybe 5.4). Using a Bayer A1cNow home-test meter (purchased online, from Walgreens), however, my A1c came up 5.8. 5.8 equates to an average of 129.2--to my mind, way out of whack (I can count on the fingers on one hand the number of times my BG was even as high as 129 during those three months, and I was testing 8-10 times a day, with an Accu-Chek Aviva that had tested within a couple of points of my lab FBG). 

I decided to hold onto my second A1CNow test until my next lab test, in September, to see how closely the A1cNow and the lab test turned out. My averages for June, July, and August were 97, 96 and 98, respectively, for an average of 97, and my average for the first three weeks of September was also 97. Based on those averages, I expected my lab-tested A1c to be no more than it was in March.  It was, in fact, minimally higher:  5.4.  The A1cNow, on the other hand, reported my A1c to be 5.9--again, 0.5% higher than my lab.