What breed are these?

[Williamsfriends]

Thank you for the replies. I hadn't heard of them either (so didn't know what they were supposed to look like) but just liked the look of them. It doesn't matter what they are to me anyway (so long as they are happy, healthy and laying!). They seem to have settled in well with our current hen (she is a lovely calm Jersey Giant) so I will release them into the garden today.
Many thanks.