Shower hose too small for wall fitting

[Yorkie23]

Hi,
I currently have a shower with an aerator attached at the wall fixings. I have just bought a new shower head with an integral aerator, so no longer need the original one. However, when I remove it, the shower hose (standard fit) no longer fits as the aerator tapers from 2cm diameter to 1.5cm. What can I use to replace the aerator to make the hose fit?
Thank you

 

[rpm]

Edited out.

 

[Chalked]

Undo the next bit, still attached to the valve. Hat will leave a 1/2 thread

 

[Yorkie23]

Undo the next bit, still attached to the valve. Hat will leave a 1/2 thread

Thank you, knew there would be a simple solution. It had got stuck on and I didn’t want to get the pliers onto it and damage it if it wasn’t supposed to come off!