Cuco Martina has become the latest player to join Everton this summer - and the defender revealed it was the club's "big ambition" shown in the transfer market that convinced him to join on a free transfer.
Martina joins a list of new recruitments including the likes of Jordan Pickford, Michael Keane and Wayne Rooney.
Martina has 30 worldwide caps for the Caribbean former Dutch colony of Curacao, who were knocked out of the CONCACAF Gold Cup on Sunday.
"We will play against Twente, one of my old clubs too, and I'm really looking forward to showing everyone what I can do".
The Toffees' regular right-back Seamus Coleman suffered a double-leg break while on global duty in March so will miss the start of this campaign, while Koeman was also keen to acquire more defensive options ahead of their return to the Europa League.
"Everton supporters are really passionate about their Club and everyone's excited about where the Club is aiming".
Everton manager Ronald Koeman added: "Cuco Martina is an experienced player who can perform in different positions at the back which is important".
'I brought the player to Southampton, so I know what he can do for us here and this is why I've now brought him to Everton.
Martina's versatility attracted Koeman to the Curacao worldwide, who made nine Premier League appearances for Southampton last season, as Everton attempt to balance European commitments with their efforts to break into the Premier League's top six.
"You can see this is a club that wants to achieve something", said Martina, who has 30 caps for the Caribbean nation of Curacao. "He is a player who will strengthen our squad and be able to play in different positions when that's needed, too".
Everton have been one of the busiest Premier League sides this summer.