According to
Ananova, what we have here is the world's oldest condom, on display in an Austrian museum. No word on why they speculate that this is the oldest, but they say it's reusable (eww!), made of pig intestine, (ewwwwwww!) and comes (ha ha) with an owner's manual written in Latin.
The article says the manual suggests that the condom user should "immerse the condom in warm milk prior to its use to avoid diseases." Did they understand the whole mechanism of disease in 1640? And if you soaked it in warm milk, what's the need for the woman? This thing looks like it has all the sensitivity of tree bark, and reminds us that there are many advantages to advances in technology.