We purchased the -25 bag with nylon on the outside. Definitely a car camping bag based on size and weight. I was initially concerned about keeping warm because when I held up the bag to light, you can see the light thru the bag! Females sleep colder than men but it kept me very warm on a 25 degree nite (wearing thin long johns under sweats). Looking forward to testing it in even colder weather. Like that these bags are so roomy, wide and long. My hubby is 6' and this bag is plenty long, comes up to his neck with no cramped feet and he still has lots of room in top of the hood (which is well padded). The description says the interior is flannel but it's not, it's just thin cotton material with a plaid print made to look like flannel and it's not all that soft, but it’s a lot warmer than a nylon interior. The bags compact down to a decent size when using the cover and end compression straps but larger than most higher temp rated bags. I found it to be a bit of a struggle to put the bag back into the cover as the bags puff up quite a bit when opened. I would call the zipper baffles almost non-existent compared to my +30 degree bag. They are very narrow with hardly any insulation in them. That said I didn't feel any drafts or cold air coming in thru the zipper. Important Note: These bags are configured differently than most other rectangular sleeping bags as the zipper is on just one side and NOT the bottom so they don't open up fully flat. That means you can't use them as a quilt/blanket. To make 2 singles into a double bag; you have to connect 2 bags together as side by side singles. But to do that you need one bag with a right zipper AND one bag with a left zipper since the hoods are not removable. The problem is I've yet to find any website that tells you what side zipper they offer or gives you a choice of right or left zipper when ordering. And because of the odd double configuration, once made, the connection zipper is down the middle of the new double bag unless you rotate the bags. So if you want to make a double bag from 2 singles or open one up to use as a blanket, this is not the bag for you. We did not purchase the bags for this purpose so over all we are happy with these bags, especially for their generous size and temp rating at this price point. We do recommend the bags.