The US Wire Extreme cord is the most flexible cord in very cord temps of any I have tested. I did not observe the kinking problem with the US Wire Extreme cord that some other reviewers have mentioned. But since the outer sheath is "grippier" (more like rubber) and more flexible than most other cords (low-temp or otherwise) I could see how it would be more likely to hang up & kink if you were trying to drag it across or around objects like bushes, etc. The US Wire Extreme cord is noticeably more flexible than its main competitor, the Prime Arctic Blue cord (e.g.: LT530730), which has an outer sheath that is slicker (more like plastic) compared to the US Wire Extreme cord's sheath, which feels grippier (much more like rubber). However, the Prime Arctic Blue cord has much higher quality ends, with nickel-plated solid blades that are less likely to corrode or bend, and the female end has a locking feature that not only holds two cords together, it also tightens the connection (unlike Cerro's "Stayplug " locking connector, which uses a different scheme). The quality of the ends is an important factor, because ends usually fail first on a cord that isn't subjected to rough handling or regularly wound too tightly (the outer sheath usually fails first on those), either by not staying attached to the cord, or developing a less-than-solid electrical connection over time, due to heating from heavy loads. The less solid the connection, the more it will heat up under load, which causes the brass to become less resilient, which makes the connection even looser, which makes it heat up more, etc. But the US Wire Extreme cord ends would be good enough if it wasn't for a manufacturing defect that I observed on three different cords (one from Amazon and two in local stores): On all three cords, the two flat blades (hot & neutral) are not straight in line with the ground prong (one of the three wasn't even close to straight). This was not due to being bent; inside the end there is a plastic "holder" molded in place at an angle, causing the two flat blades to be angled. The cord that was the worst of the three had such a misalignment that the two ends were difficult to plug together fully. And yet if I offset the cord ends so I could plug in just ONE blade at a time (see last photo), the connection was fairly loose, noticeably looser than any of the non-locking Prime cords (e.g.: EC501730) I tested. While it is possible to bend the blades on US Wire Extreme male plug end to compensate for this, users should not have to do that to a brand new cord. Another problem: two of the three US Wire Extreme cords I examined and photographed had voids (air bubbles) in the female ends. Over time this might cause the internal components to loosen up. While it's probably not a big problem, it is another example of poor QC in the production of these US Wire cords. I looked at a total of four Prime cords, and none of those had any problems like this. The ends were straight and even without Prime's locking feature, they all made tighter connections than the US Wire Extreme cords. My 3-star rating is based on an assumption that the defects I observed in the three cords I examined were not typical for all US Wire cords. I have to wonder about that though, since the three cords were two different lengths and in three different stores (meaning they probably were not from the same production batch). If most US Wire Extreme cords do have these manufacturing defects, I'd have to rate it lower; if most do not have these manufacturing defects, I'd rate it four stars, and recommend it as the best choice for anyone who wants the most flexible low-temperature cord, even if the design of the ends is not as rugged nor connect as solidly as Prime's comparable cords. UPDATE: The photos I posted showed up for a couple days but now seem to have disappeared (something I've seen happen before on some of my other Amazon reviews). So here are links to those photos on a more reliable image host site: [...] The first three photos show the blade alignment defects in the plug (male) ends on three different US Wire Extreme cords: [...] [...] [...] The next two photos show the "void" (trapped air bubbles) defects in the cap (female) ends on one US Wire Extreme cord: [...] [...] and this shows the two ends of the worst US Wire Extreme cord plugged together. [...] Single blade test method: [...] This photo shows the relative flexibility of the Prime Arctic Blue cord compared to the US Wire Extreme cord (both in their original packages) after a few hours in a freezer that was probably no colder than 10°F: [...] Just the weight of a few feet of cord is enough to make the US Wire Extreme cord nearly straight, whereas the bends in Prime Arctic Blue cord remained more prominent.
