Jacob the Jeweler had designed this three-carat cushion-cut diamond set in platinum above double shank band with 210 round pave diamonds (pictured here), according to Angela Arabo, Jacob & Co vice president, who worked with Kevin to design the ring. The star “had done his homework,” Arabo said. “He knew exactly what he wanted.” The two collaborated over the phone and email. “When he got the ring, he called me and said it was the most beautiful ring and it was exactly how he imagined. He was really excited. He couldn’t wait to propose to her.” Kevin Jonas, 21, proposed to Deleasa, 22, surprising her at her doorstep early on Wednesday morning — flying overnight after a Jonas Brothers concert in Vancouver.