Slightly aghast at what our house sitters have left in the fridge. Got back from hols yesterday and due to logistics they’d already gone.
Anyway I have had to google it - but there were three packets of ‘nuvaring’ in my fridge 
According to a well known search engine is It’s a plastic ring you insert vaginally - so a topical contraceptive.
I am slightly embarrassed for them but also had never heard of it!
Slightly less 
than the semen-soaked towel a certain young relative and girlfriend left in he bed when they stayed.