These condoms are made of polyisoprene, which is lovely for a number of reasons:
-It circumvents any latex allergies
-It is a bit of a stronger material than latex, so less likelihood of breaking
-They protect against STIs as well as pregnancy, unlike lamb skin which only does the latter(though like any other condom, it is NOT 100% effective in either form of protection. Do your research and play safe kids.)
-The material is cheaper and stretchier than polyurethane, which is your other common nonlatex option

The condoms come pre-lubed on both sides--water based lube. The lubrication is very slight though, so if you need more than whatever wetness you produce naturally this isn't going to be sufficient. A big benefit of this, however, is that there isn't a very strong taste or smell. This makes them a nifty condom for giving oral without having to drown your partner's cock in chocolate sauce or jam or whatever else normally helps you make lube taste palatable.
While we're on the subject, it is worth mentioning that you cannot use these condoms with oil-based lube.

As many others have said, Skyn condoms are not actually thinner than most condoms, and do not live quite up to their claim of a bareback feeling. The aforementioned stretchiness, however, makes them a snug and comfortable fit on your average sized penis. This along with the material is what transfers sensation better than many other non-latex options (I do not have much experience with latex options, so cannot attest to how they hold up in this area). My partner has a latex allergy, and was quite pleasantly surprised with these.

All in all, a great condom; but don't get them because you're expecting to simulate a bareback experience. Get them because they're one of the best non-latex options currently available (particularly if you can find them for cheap in bulk!)

My partner has a latex allergy and I ordered these so that we could practice safer oral sex. For that purpose, they were wonderful. He had been worried that oral with a condom on would not generate nearly enough sensation. After our first time trying them, however, he got this surprised look on his face and went "Huh! I could actually feel quite a bit. I was afraid this was going to suck." As mentioned in the main review, the taste and smell is also pretty subtle (and not, to me, unpleasant) so things were comfortable for me as the oral-giver. These have since become my go-to condom.