They seem to hit shops sporadically and usually without warning and typically don't make it past a day or two. At least that's how it's been the last few times I've seen them arrive at my local. The last two boxes showed up with the UF13s along with two boxes of Dirty Rats. Needless to say all of the above mentioned sticks were sold out in two days and that was with limits set. Even when I see e-mails from online vendors come through it usually is followed by an e-mail time stamped 3 or 4 minutes later saying they are sold out. This is why I am glad I hoarded two boxes and am rationing them out accordingly.
