The ride will be the first StarFlyer in Sweden, and is described as 121 meters tall or about 397 feet. Grona Lund is located along the water adjacent to Stockholm, so the views from the top of Eclipse are going to be pretty hard to beat.
Eclipse's construction is already well underway, with the base of the tower already in place. There is a construction movie and webcam available on the ride's official website. Seen above in concept art form, the ride will have a decorative top piece and flag pole, as well. Eclipse is expected to open at Grona Lund on April 27th.
Previously the tallest StarFlyer was the Prater Tower in Austria, which stands 384 feet. Six Flags Over Texas is currently building the Texas SkyScreamer, which is advertised at 400 feet - and also billed as the tallest in the world. I'll let it to Grona Lund and Six Flags Over Texas to duke it out over who really holds the record.