Arsenal have secured the signature of Cristhian Mosquera for a reported €15 million fee plus add-ons.The Spaniard makes the move from Valencia to London – and joins on a five-year contract plus an option of further year.The 21-year-old becomes Arsenal’s fifth signing of the summer, after Kepa Arrizabalaga, Martin Zubimendi, Christian Norgaard and Noni Madueke.”It means a lot to me, There’s been a lot of hard work behind all of this.”It’s an opportunity that came up and I couldn’t let it pass me by. I’m joining a historic, massive club. When you arrive here with your family, you really feel the greatness of this place,” Mosquera said.”We’re delighted to welcome Cristhian to Arsenal. As a 21-year-old defender, Cristhian has already performed consistently well with significant experience in La Liga. He is an intelligent player with good pace, who can play centrally and on both sides.”He is a young player with exciting talent and enormous potential, who will fit well into our squad as we continue to prepare for next season. Cristhian adds good quality to our squad, and we look forward to working with him and making him feel at home with us.”From all of us, we welcome Cristhian and his family to the club,” Arsenal manager, Mikel Arteta spoke of Mosquera.