West Ham have signed Lazio attacking midfielder Felipe Anderson for a club record fee of around £40 million.
Anderson, 25, joins Manuel Pellegrini's side on a four-year contract and the deal smashes the £24m West Ham paid to sign France defender Issa Diop earlier this window.
The Brazilian becomes West Ham's seventh signing of the summer so far after Ryan Fredericks, Lukasz Fabianski, Diop, Jack Wilshere, Andriy Yarmolenko and Fabian Balbuena.
"I feel really happy and fulfilled to join West Ham United," Anderson told the official club's website. "West Ham is a club with a lot of tradition, lots of great players have played here, like Bobby Moore, Carlos Tevez and Di Canio.
"They were great players and idols here, and I'm aiming big, who knows, maybe I could hit their heights and be a legend here too. I'm really happy to be here. It's a dream come true.
"I want to thank the owner, David Sullivan, because he made a big effort to bring me here. I know how difficult it was, so I have to thank him a lot, and I hope I can repay his faith in me on the pitch with goals and winning games."
Joint-Chairman Sullivan added: "Felipe was a main target of the manager so we are delighted we've been able to bring him to the Club.
"We're very pleased with the business we've done so far and I hope the supporters are just as excited as we are about the squad we are building here at West Ham.
"The deal sees us significantly break our transfer record and we feel it's a real statement of intent."