Which way round does this go on the steriliser?!

[tyuioS]

There’s these prongs are they on the side to make an air vent or should the other side be closed off? Milton steriliser unit…

Inside the tub I believe (that’s how we used these in the NICU)

@Fedupmum21 but which way does the lid sit? With the prongs allowing airflow or should the lip be closed off?

They're there to allow you to empty the water with the lid still on, so should go at the side with the lip. But it doesn't really matter, there doesn't need to be airflow or anything.