Which size MCUK should I buy?

Choose the right size MCUK for you by following the simple guidelines below:


Choose size A if you:

Are 30 and over


 Have given birth vaginally at any age


Choose size B if you:

Are under 30 and have not given birth vaginally

The size you choose

– is related to your childbearing history and your age as these can affect pelvic floor tone

– is not related to menstrual flow

Size A is 3mm bigger than size B – a small difference but it is important!

If you’re not sure which size to go for, please get in touch with our Advice team.


  • Size A measures 46mm in diameter and 50mm in length.
  • Size B measures 43 mm in diameter and 50mm in length.

Both sizes have a stem 21mm long, which you can trim to the length that is right for you.

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