Four of these five devices. Good quality. They are within about 10% of each other and about 5% of the specifications. One unit is very, very far from the left edge, to the point where I had to check the parts label to make sure it was in the same family. It's about 50% off spec in almost every way you can look at it. (Yes, I am aware that some of these parameters are non-linear, approximate values are given for this review.) The element impedance is +55% higher than the static FC specification. The temperature curve is much flatter (temp xv current y, in both directions). At 12V emissivity I see around 6.5A (while others are between 11.5-12.05A). So it's either a mislabeled 12706 core or a defect severe enough to reduce the load by more than 50% without breaking the circuit, which in my experience isn't common on smaller, cheaper modules is. Not quite sure what happened. there. But I wouldn't recommend using them, at least not without extensive dyno testing and probably not for anything critical. (Probably best to go to Bolsen for reliability and quality control). I am a multidisciplinary engineer with credentials and experience. I use this level of detail in hobbyist prototypes or non-critical projects.