The sample compasses have been personally tested to -20F. I would expect it to work at lower temps, but it has not been tested any lower by me.

I am not at liberty to reveal the manufacturer, but it does not come from Sun. As you note, the Pyser-SGI FB-1605 15mm dry NATO compass costs more than the whole rest of the kit. I will readily admit that the compass we use is not as good as that compass or some others we have looked at, but it is adequate for most circumstances, better by far than others we examined that cost the same or less or which are used in competitively priced and sized kits and the cost is within the limits necessary to keep the kit affordable. Anything else we have seen to date that is noticeably better in any respect is a mutlifold increase in price and would significantly adversely impact the cost of the PSP. We continue to search for better at an affordable cost.

Hope this answers your question