Actress Sofia Vergara thinks her engagement ring is "perfection" and says fiance Joe Manganiello picked it out all by himself.

The `Modern Family` actress, who is set to marry `Magic Mike XXL` star Joe Manganiello, 38, in Miami next month after getting engaged last December, had no idea he was going to propose at the time and says he selected the seven-carat oval diamond all by himself, reports femalefirst.co.uk.

Asked about the impressive piece of jewellery, the 43-year-old star said: "It is perfection. He picked it for me, and I wouldn't change anything. He knows that I like big."

Vergara is planning to treat their wedding day like a red carpet event and while she was initially very involved int he planning, she's leaving the final details up to her wedding planner.

"The only thing I know for sure is it's going to happen, and it's going to be a big wedding because I have a big family. For me it's going to be like a red carpet appearance. I'm just going to show up,` she said.