Hi Redflare,
I'm just guessing and assuming that you're connected with Redflarekits.com". So I thought I might let you know this....
When you arrive at the link you posted, there is no price for the Bivvy Sack and no way to add it to the Cart. You actually have to click on another product (in my case the Survival Blankets) and then it's listed in the "related items" section down below. I know it's a minor thing, but I thought maybe the company wasn't aware of that.

Anyway, I went there and bought 2 Bivvy Sacks and 3 Survival Blankets. I carry several "Listos" brand blankets (made in USA which, for some reason, is very important to me), and I'm really looking forward to trying out the Bivvy Sacks.

Thanks for the link!

Weird, It works fine with me. There is an "add to order" button and prices above it. Here is that link again: Emergency bivvy sacks
What version and which browser do you use?
Possibly, the button could be off the screen on the right, because the picture is too big, I'll fix it.
thanks for point this out. <img src="/images/graemlins/cool.gif" alt="" />

Well Redflare, how about that. I used your link and went to the site. There was the price and "Add to Basket" button, scary as a snakes fangs, right where it ought to be. I swear I hunted all over that page for the price the first time, but I surely could have missed it. Sorry about that!

I tried doing that the other night. It was raining; I found the wet grass sucked the heat out of me through the bivvy. The material is thin and offers no insulation against conduction. I quickly moved under some trees, where there was a bed of pine needles. This was much warmer (and dryer).

The twigs poked a dozen or so holes in the material, but that didn't seem to matter much at the time. The holes didn't grow. I've now put duct tape over the worst of them and left the others. I think the bivvy is still usable but I've swapped it out of my everyday carry.

I spent about 90 minutes on the test. I was wearing thin office trousers, and wasn't really comfortable enough to spend the night by choice.

I was impressed by their small size when carried and large size in use. In use they are about 7'x3', which is easily enough to lie full length with your head covered. Much better than any ordinary plastic bag I've found. When carried they are small enough to fit in a tin mug with room over. I found I could re-pack them easily (indoors) - any trapped air somehow escapes and it's no trouble putting them back into their bag. I have chosen to fold mine rather than roll it, to make a flatter form-factor which will fit better into my EDC waist-pack.

It's best to have a pee before you get into the bivvy. Don't get in, lie there for an hour and then think to yourself, "I'd really like to have a pee now."

Overall I'd strongly recommend them, so long as you are realistic about their limitations.