FYI...The female condom DOES IN FACT prevent transmission of STD's.

I have one right in front of me and the packaging specifics state "Intended to provide protection against pregnancy and sexually transmitted disease, including AIDS (HIV infection)."

Female condoms are made from polyurethane and will work with any type of lubricant (penzoil if you so wish).

I've used them many times as the receptive partner and they work well. I highly doubt one would work if being screwed by an endowed man as he would bottom out and just shove the thing way up in there. With an average sized guy they are great. The insertive partner gets good friction and sensation. Good times, man!