Question about micro sterilisers

[Deb111]

I have just bought a tommee tippee essential basics micro steriliser. I know other micro ones I've seen have vents but this one doesn't. It does however have a disc about an inch and a half in diameter that comes out. However there is no mention of this disc in instruction. I don't just want to remove it in case it stops it being properly sterile but can't see the point of it being there otherwise. Any ideas?

 

[silver lady]

I would look on Tommie tippee site or ring and ask them x

 

[Deb111]

Thanks. Website doesn't even show item. Google search shows nothing and customer services took a week to get back to me to last time i phoned as you always have to leave a message. I have left a message but no reply yet.