Arsenal defender Shkodran Mustafi says he will "grow as a player" during his time at the Emirates.
The Germany international has joined the Gunners for a reported fee of more than £35million.
His transfer was officially announced by the club on the same day they announced the signing of striker Lucas Perez.
Mustafi could make his official debut for the club on September 10 against Southampton.
"I'm happy [to be at Arsenal]," he told Arsenal's official website.
"It took some time but finally I'm here and I'm happy to have made a step forward in my career again, because I think it is a step forward to have joined this club. I hope I'm going to have a great time here.
"When I came to England [to play for Everton], I was quite young. I was only 17 and it's not easy when you come to a different country with a different language, a different culture and a different style of football. The main thing was that I grew up. From a boy, I became a man.
"The way you play football here, the way that you don't have excuses for things made me grow up.
"When you change team, obviously you try to always make a step forward.
"I think coming here I've made a step forward, because Arsenal is a big club with big players and a great manager.
"For me I think the most important thing was if I made a change, could I learn something? Was it going to be good for my development? I think that being here now is going to help me grow as a player."