Menstrual cups are small foldable cups inserted i persons vagina to catch menstrual fluids (blood and womb lining) menstrual cups should be emptied every 4-12 hrs and can be sterilised at the end of a period by boiling in water. If you want some information on how you fold a menstrual cup to put it inside your vagina
There are lots of different kinds of menstrual cups
The cup effect allow you to buy a menstrual cup and one will be donated to someone who cant afford one.
Feminine wear stock a wide range of menstruation related products
Boots or Superdrug sell menstrual cups they are not always available in physical stores but are available online
If you need a latex cup rather then a silicon menstrual c up the keeper cup would be a good choice
Australia and New Zealand
Menstrual cups australia online
Here are a couple of places you can find comparison charts.