Sunderland Complete Dutch International Signing.
The fee is said to be somewhere around the £8m mark for a player who is just as comfortable on the wing as he is playing up front.
The 27 year old has played under Dick Advocaat before at PSV Eindhoven and AZ Alkmaar.
Speaking to Sunderland's official website Advocaat said: 'We have signed an international player and I am delighted to welcome him to Sunderland.'
He added: 'I have worked with him twice already, at PSV and AZ, so I know him well; he is fast and he has scored goals everywhere he has played so that will help the team.'
As well as making over 30 appearances for the Dutch national side, Lens also has Champions League and Europa League experience to bring to the Sunderland squad.
The video clip below shows just a taste of what the new man can do